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{{Short description|Proposed condition wherein human numbers exceed the carrying capacity of the environment}}
{{redirect2|Overpopulate|Overpopulating|the general concept of overpopulation|Overpopulation}}
{{Distinguish|Population growth}}
{{Use dmy dates|date=September 2012}}
{{Use dmy dates|date=December 2023}}
]. It shows the extremely rapid growth in the world population that has taken place since the eighteenth century.]]
<!-- Deleted image removed: ] -->
].'')]]
<!--Please consider adding new content to a relevant section of the article body, not the lead. The lead section should summarise each section of the article. See ] for guidance.-->'''Human overpopulation''' (or '''human ]''') is the idea that human ]s may become too large to be ] by their environment or resources in the long term. The topic is usually discussed in the context of ], though it may concern individual nations, regions, and cities.
]
] (See ''].'')]]
]


<!--Background and Key concepts-->Since 1804, the global living human population has ] due to ] and improved ]. Annual world population growth peaked at 2.1% in 1968 and has since dropped to 1.1%.<ref name="OWOD2019"/> According to the most recent ], the global human population is expected to reach 9.7 billion in 2050 and would peak at around 10.4 billion people in the 2080s, before decreasing, noting that ] are falling worldwide.{{r |n="UN Projections-2022" |r={{cite report|title= World Population Prospects 2022: Summary of Results |publisher= United Nations Department of Economic and Social Affairs, Population Division |id = UN DESA/POP/2022/TR/NO.3 |date=2022| url = https://www.un.org/development/desa/pd/sites/www.un.org.development.desa.pd/files/wpp2022_summary_of_results.pdf}}|pages=14-30}} Other models agree that the population will stabilize before or after 2100.<ref name="Roser-2013" /><ref name="Vollset-2020"/><ref name="Science"/> Conversely, other researchers have found that ] data from 2022 and 2023 that cover half the world's population indicate that the 2022 UN projections overestimated fertility rates by 10 to 20% and are already outdated, that the global fertility rate has possibly already fallen below the ] level for the first time in human history, and that the global population will peak at approximately 9.5 billion by 2061.<ref>{{cite news|last1=Ip|first1=Greg|last2=Adamy|first2=Janet|date=13 May 2024|title=Suddenly There Aren't Enough Babies. The Whole World Is Alarmed.|work=The Wall Street Journal|publisher=News Corp|url=https://www.wsj.com/world/birthrates-global-decline-cause-ddaf8be2|access-date=13 May 2024}}</ref> The 2024 UN projections report estimated that world population would peak at 10.29 billion in 2084 and decline to 10.18 billion by 2100, which was 6% lower than the UN had estimated in 2014.<ref>{{cite news|last=Shan|first=Lee Ying|date=11 July 2024|title=Global population to peak within this century as birth rates fall, United Nations report says|publisher=CNBC|url=https://www.cnbc.com/2024/07/12/world-population-to-peak-within-this-century-says-the-united-nations.html|access-date=12 July 2024}}</ref><ref>{{cite news|last=Dougherty|first=Danny|date=11 July 2024|title=Earth's Population Should Peak Before the End of the Century|work=The Wall Street Journal|publisher=News Corp|url=https://www.wsj.com/world/its-official-earths-population-should-peak-before-the-end-of-the-century-81bbd498|access-date=12 July 2024}}</ref><ref>{{cite report|title=World Population Prospects 2024: Summary of Results|date=11 July 2024|publisher=United Nations Department of Economic and Social Affairs, Population Division|url=https://population.un.org/wpp/Publications/Files/WPP2024_Key-Messages.pdf|access-date=12 July 2024}}</ref>
'''Human overpopulation''' occurs when the ] of a human population in a specific geographical location exceeds the ] of the place occupied by that group. Overpopulation can further be viewed, in a long term perspective, as existing when a population cannot be maintained given the rapid depletion of ] or given the degradation of the capacity of the environment to give support to the population.<ref>{{cite book|last1=Ehrlich|first1=Paul R. Ehrlich & Anne H.|title=The population explosion|date=1990|publisher=Hutchinson|location=London|isbn=0091745519|pages=39–40|url=http://www.ditext.com/ehrlich/title.html|accessdate=20 July 2014|quote=When is an area overpopulated? When its population can not be maintained without rapidly depleting nonrenewable resources (or converting renewable resources into nonrenewable ones) and without decreasing the capacity of the environment to support the population. In short, if the long-term carrying capacity of an area is clearly being degraded by its current human occupants, that area is overpopulated.}}</ref>


<!--History of concept-->Early discussions of ] in English were spurred by the work of ]. Discussions of ] follow a similar line of inquiry as ],<ref name="Scientific American">{{cite web|title=Human Overpopulation: Still an Issue of Concern?|url=https://www.scientificamerican.com/article/human-overpopulation-still-an-issue-of-concern/|access-date=13 March 2021|website=Scientific American|language=en}}</ref><ref name="10.1080/01436597.2014.926110">{{Cite journal|last1=Fletcher|first1=Robert|last2=Breitling|first2=Jan|last3=Puleo|first3=Valerie|date=9 August 2014|title=Barbarian hordes: the overpopulation scapegoat in international development discourse|url=https://doi.org/10.1080/01436597.2014.926110|journal=Third World Quarterly|volume=35|issue=7|pages=1195–1215|doi=10.1080/01436597.2014.926110|issn=0143-6597|s2cid=144569008}}</ref> a hypothetical event where population exceeds agricultural capacity, causing ] or ] over resources, resulting in ] and depopulation. More recent discussion of overpopulation was popularized by ] in his 1968 book '']'' and subsequent writings.<ref name="Ceballos2017" /><ref>{{Cite journal |last1=Ehrlich |first1=Paul |last2=Ehrlich |first2=Anne |date=2013 |title=Can a collapse of global civilization be avoided? |journal=Proceedings of the Royal Society B: Biological Sciences |volume=280 |issue=1754 |pages=20122845 |doi=10.1098/rspb.2012.2845|pmid=23303549 |pmc=3574335 |s2cid=2822298 }}</ref> Ehrlich described overpopulation as a function of ],<ref>{{cite web|author1=Paul Ehrlich|author2=Anne H. Ehrlich|date=4 August 2008|title=Too Many People, Too Much Consumption|url=https://e360.yale.edu/features/too_many_people_too_much_consumption|access-date=9 January 2021|website=Yale Environment 360|publisher=Yale School of the Environment}}</ref> arguing that overpopulation should be defined by a population being unable to sustain itself without depleting ]s.<ref name="Ehrlich-1990">{{cite book|last1=Ehrlich|first1=Paul R. Ehrlich & Anne H.|url=https://archive.org/details/populationexplos00ehrl/page/39|title=The population explosion|date=1990|publisher=Hutchinson|isbn=978-0091745516|location=London|pages=|quote=When is an area overpopulated? When its population cannot be maintained without rapidly depleting nonrenewable resources (or converting renewable resources into nonrenewable ones) and without decreasing the capacity of the environment to support the population. In short, if the long-term carrying capacity of an area is clearly being degraded by its current human occupants, that area is overpopulated.|access-date=20 July 2014}}</ref><ref>{{citation|last1=Ehrlich|first1=Paul R|title=One with Nineveh: Politics, Consumption, and the Human Future|date=2004|pages=76–180, 256|publisher=Island Press/Shearwater Books|last2=Ehrlich|first2=Anne H|author-link1=Paul R. Ehrlich|author-link2=Paul R. Ehrlich}}</ref><ref>{{citation|last1=Ehrlich|first1=Paul R|title=Healing the Planet: Strategies for Resolving the Environmental Crisis|date=1991|pages=6–8, 12, 75, 96, 241|publisher=Addison-Wesley Books|last2=Ehrlich|first2=Anne H|author-link1=Paul R. Ehrlich|author-link2=Paul R. Ehrlich}}</ref>
The term ''human overpopulation'' refers to the relationship between the ] and its ]: the Earth,<ref>" {{webarchive |url=https://web.archive.org/web/20160429094959/https://www.theguardian.com/environment/2007/aug/31/climatechange.food |date=29 April 2016 }}". Guardian.co.uk (2007-08-31).</ref> or to smaller geographical areas such as countries. Overpopulation can result from an increase in ], a decline in ]s, an increase in ], or an ] ] and depletion of resources. It is possible for very sparsely populated areas to be overpopulated if the area has a meagre or non-existent capability to sustain life (e.g. a ]). Advocates of population moderation cite issues like ], ], and risk of ] as a basis to argue against continuing high human population growth and for ]. Scientists suggest that the ] as a result of overpopulation, profligate ] and proliferation of technology has pushed the planet into a new geological ] known as the ].<ref>{{cite web |url=https://phys.org/news/2015-03-coping-anthropocene.html|title= Coping with the Anthropocene|first= |last= |date=March 17, 2015|work=]|accessdate=January 23, 2017}}</ref><ref>{{cite web |url=https://www.theguardian.com/environment/2016/jan/07/human-impact-has-pushed-earth-into-the-anthropocene-scientists-say|title=Human impact has pushed Earth into the Anthropocene, scientists say|first=Adam |last=Vaughan|date=January 7, 2016|work=]|accessdate=January 23, 2017}}</ref><ref>{{cite web |url=http://news.nationalgeographic.com/news/2014/09/140920-population-11billion-demographics-anthropocene/|title=As World’s Population Booms, Will Its Resources Be Enough for Us?|first=Dennis |last=Dimick|date=September 21, 2014|work=]|accessdate=January 23, 2017}}</ref>


<!--Debate-->The belief that global population levels will become too large to sustain is a point of contentious debate. Those who believe global human overpopulation to be a valid concern, argue that increased levels of ] and pollution exceed the environment's ], leading to population ].<ref name="Crist2022" /> The population overshoot hypothesis is often discussed in relation to other population concerns such as ], ],<ref>{{Cite journal |last1=Brashares |first1=Justin |last2=Arcese |first2=Peter |last3=Sam |first3=Moses |date=2001 |title=Human demography and reserve size predict wildlife extinction in West Africa |journal=Proceedings of the Royal Society of London. Series B: Biological Sciences |volume=268 |issue=1484 |pages=2473–2478 |doi=10.1098/rspb.2001.1815|pmid=11747566 |pmc=1088902 }}</ref><ref>{{cite journal |last1=Cafaro |first1=Philip |last2=Hansson |first2=Pernilla |last3=Götmark |first3=Frank |title=Overpopulation is a major cause of biodiversity loss and smaller human populations are necessary to preserve what is left |journal=] |date=2022 |volume=272 |pages=109646 |doi=10.1016/j.biocon.2022.109646}}</ref> ],<ref>{{Cite journal |last1=Daily |first1=Gretchen |last2=Ehrlich |first2=Anne |last3=Ehrlich |first3=Paul |date=1994 |title=Optimum human population size |journal=Population and Environment |volume=15 |issue=6 |pages=469–475|doi=10.1007/BF02211719 |s2cid=153761569 }}</ref> ], and the overall ].<ref name="Dasgupta2019">{{Cite book |last=Dasgupta |first=Partha |title=Time and the Generations: Population Ethics for a Diminishing Planet |publisher=Columbia University Press |year=2019}}</ref>
==Overview==
] has been growing continuously since the end of the ], around the year 1350,<ref>{{cite web|url=http://www.abc.net.au/science/articles/2008/01/29/2149185.htm |title=Archived copy |accessdate=2008-11-03 |deadurl=no |archiveurl=https://web.archive.org/web/20161220120404/http://www.abc.net.au/science/articles/2008/01/29/2149185.htm |archivedate=20 December 2016 |df=dmy }}</ref> although the most significant increase has been since the 1950's, mainly due to ] and increases in agricultural productivity. The rate of population growth has been declining since the 1980s, while the absolute total numbers kept increasing. Recent rate increases in several countries previously enjoying steady declines are also apparently contributing to continued growth in total numbers. The ] has expressed concerns on continued population growth in ].<ref name="bbc.co.uk">{{cite news|url=http://www.bbc.co.uk/news/world-15459643 |title=BBC News – Population seven billion: UN sets out challenges |publisher=BBC |date=2013-05-22 |accessdate=2011-11-30}}</ref> Recent research has demonstrated that those concerns are well grounded.<ref name="cliodynamics.ru">Zinkina J., ] {{webarchive |url=https://web.archive.org/web/20160823153527/http://cliodynamics.ru/index.php?option=com_content&task=view&id=360&Itemid=1 |date=23 August 2016 }}.</ref> As of {{CURRENTMONTHNAME}} {{CURRENTDAY}}, {{CURRENTYEAR}} the world's human population is estimated to be {{Formatnum:{{#expr: {{data world|poptoday}} / 10^9 round 3}}}}&nbsp;] by the ],<ref name=USCBcite>{{cite web |url=http://www.census.gov/popclock |title=U.S. and World Population Clock|accessdate=2016-03-05}}</ref> and over 7 billion by the ].<ref name=UN7bn>{{cite news|url=http://www.bbc.co.uk/news/world-15459643 |title=Population seven billion: UN sets out challenges|date=2011-10-26|publisher=BBC|accessdate=2011-10-27}}</ref><ref>{{cite news|url=https://www.theguardian.com/world/2011/oct/31/seven-billionth-baby-born-philippines?intcmp=122 |title=World's 'seven billionth baby' is born|date=2011-10-31|work=The Guardian |accessdate=2011-10-31|location=London|first=Jasmine|last=Coleman}}
</ref><ref>{{cite web|title=7 billion people is a 'serious challenge'|url=http://www.upi.com/Top_News/US/2011/10/31/7-billion-people-is-a-serious-challenge/UPI-73301320046200|website=http://www.upi.com/}}</ref> Most contemporary estimates for the carrying capacity of the ] under existing conditions are between 4 billion and 16 billion. Depending on which estimate is used, human overpopulation may or may not have already occurred. Nevertheless, the rapid recent increase in human population is causing some concern. The population is ] to reach between 8 and 10.5 billion between the years 2040<ref>{{cite web|url=http://www.worldometers.info/population/ |title=World Population Clock – Worldometers |publisher=Worldometers.info |accessdate=1 August 2010}}</ref><ref>{{cite web|url=http://www.census.gov/ipc/www/idb/worldpopinfo.php |title=International Data Base (IDB) – World Population |publisher=Census.gov |date=2010-06-28 |accessdate=1 August 2010}}</ref> and 2050.<ref name=UN>{{cite web |url=https://www.un.org/esa/population/publications/popnews/Newsltr_87.pdf |title=World Population Prospects:The 2008 Revision |publisher=] |date=June 2009}}</ref> In May 2011, the United Nations increased the medium variant projections to 9.3 billion for 2050 and 10.1 billion for 2100.<ref>{{cite web |url=http://esa.un.org/unpd/wpp/Other-Information/Press_Release_WPP2010.pdf |title=World Population Prospects:The 2010 Revision Press Release |publisher=] |date=May 2011}}</ref>


Critics of the belief note that human population growth is decreasing and the population will likely peak, and possibly even begin to decrease, before the end of the century.{{r|UN Projections-2022|p=27}} They argue the concerns surrounding population growth are overstated, noting that quickly declining birth rates and technological innovation make it possible to sustain projected population sizes. Other critics claim that overpopulation concerns ignore more pressing issues, like poverty or ], are motivated by racism, or place an undue burden on the ] where most population growth happens.<ref name="Rao-1994"/><ref name="Monbiot-2021"/>
The recent rapid increase in human population over the past three centuries has raised concerns that the planet may not be able to sustain present or future numbers of inhabitants. The ], circa 1994, stated that many environmental problems, such as rising levels of ], ], and ], are aggravated by the population expansion.<ref>{{cite web|title=joint statement by fifty-eight of the world's scientific academies |url=http://www.interacademies.net/?id=3547 |deadurl=yes |archiveurl=https://web.archive.org/web/20100210203604/http://www.interacademies.net/?id=3547 |archivedate=10 February 2010 }}</ref> Other problems associated with overpopulation include the increased demand for resources such as fresh water and food, ] and ], consumption of natural resources (such as ]) faster than the rate of regeneration, and a deterioration in living conditions. Wealthy but highly populated territories like ] rely on food imports from overseas.<ref>{{cite web|last1=WRIGHT|first1=OLIVER|title=Britain's food self-sufficiency at risk from reliance on overseas imports of fruit and vegetables that could be produced at home|url=http://www.independent.co.uk/news/uk/politics/britains-food-selfsufficiency-at-risk-from-reliance-on-overseas-imports-of-fruit-and-vegetables-that-could-be-produced-at-home-9574238.html|website=http://www.independent.co.uk|accessdate=11 July 2014}}</ref> This was severely felt during the ] when, despite food efficiency initiatives like "]" and ], Britain needed to ]. However, many believe that waste and ], especially by wealthy nations, is putting more strain on the environment than overpopulation.<ref>{{cite web|url=http://e360.yale.edu/feature/consumption_dwarfs_population_as_main_environmental_threat/2140/ |title=Consumption Dwarfs Population as Main Environmental Threat|author=Fred Pearce|publisher=Yale University |date=2009-04-13|accessdate=2012-11-12}}</ref>


== Overview ==
Most countries have no direct policy of limiting their birth rates, but the rates have still fallen due to education about family planning and increasing access to birth control and contraception. Only ] had imposed ]. ] and other technical solutions have been proposed as ways to mitigate overpopulation in the future.
<!--Proposed impacts and proposed mitigation-->Modern proponents of the concept have suggested that overpopulation, population growth and overconsumption are interdependent<ref>{{cite journal |last1=Bradshaw |first1=Corey J. A. |last2=Ehrlich |first2=Paul R. |last3=Beattie |first3=Andrew |last4=Ceballos |first4=Gerardo |last5=Crist |first5=Eileen |last6=Diamond |first6=Joan |last7=Dirzo |first7=Rodolfo |last8=Ehrlich |first8=Anne H. |last9=Harte |first9=John |last10=Harte |first10=Mary Ellen |last11=Pyke |first11=Graham |last12=Raven |first12=Peter H. |last13=Ripple |first13=William J. |last14=Saltré |first14=Frédérik |last15=Turnbull |first15=Christine |last16=Wackernagel |first16=Mathis |last17=Blumstein |first17=Daniel T. |date=2021 |title=Response: Commentary: Underestimating the Challenges of Avoiding a Ghastly Future |journal=Frontiers in Conservation Science |volume=2 |issue= |pages= |doi=10.3389/fcosc.2021.700869 |doi-access=free|quote=On the contrary, we devoted an entire section to the interacting and inter-dependent components of overpopulation and overconsumption, which are, for instance, also central tenets of the recent Economics of Biodiversity review (Dasgupta, 2021). Therein, the dynamic socio-ecological model shows that mutual causation drives modern socio-ecological systems. Just as it is incorrect to insist that a large global population is the sole underlying cause of biodiversity loss, so too is it naïve and incorrect to claim that high consumption alone is the cause, and so forth.}}</ref><ref name="Dasgupta">{{cite web |url=https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/957629/Dasgupta_Review_-_Headline_Messages.pdf |title=The Economics of Biodiversity: The Dasgupta Review Headline Messages |last=Dasgupta |first=Partha |author-link= Partha Dasgupta |date=2021 |website= |publisher=UK government| page=3|access-date=15 December 2021 |quote=Growing human populations have significant implications for our demands on Nature, including for future patterns of global consumption.}}</ref><ref>{{cite news |last=Carrington |first=Damian |date=2 February 2021 |title=Economics of biodiversity review: what are the recommendations? |url=https://www.theguardian.com/environment/2021/feb/02/economics-of-biodiversity-review-what-are-the-recommendations |work= ]|location= |access-date=15 December 2021}}</ref> and collectively are the primary drivers of human-caused environmental problems such as ]<ref>{{Cite journal |last1=O’Neill |first1=Brian C. |last2=Jiang |first2=Leiwen |last3=Gerland |first3=Patrick |date=10 February 2015 |title=Plausible reductions in future population growth and implications for the environment |journal=Proceedings of the National Academy of Sciences |language=en |volume=112 |issue=6 |pages=E506 |doi=10.1073/pnas.1421989112 |issn=0027-8424 |pmc=4330723 |pmid=25617373|bibcode=2015PNAS..112E.506O |doi-access=free }}</ref><ref>{{Cite journal |last1=O'Neill |first1=Brian C. |last2=Dalton |first2=Michael |last3=Fuchs |first3=Regina |last4=Jiang |first4=Leiwen |last5=Pachauri |first5=Shonali |last6=Zigova |first6=Katarina |date=12 October 2010 |title=Global demographic trends and future carbon emissions |journal=Proceedings of the National Academy of Sciences |language=en |volume=107 |issue=41 |pages=17521–17526 |doi=10.1073/pnas.1004581107 |issn=0027-8424 |pmc=2955139 |pmid=20937861|bibcode=2010PNAS..10717521O |doi-access=free }}</ref> and ].<ref name="Cafaro2022" /><ref>{{Cite book |last=Beebee |first=Trevor J. C. |url=http://dx.doi.org/10.1017/9781108985260 |title=Impacts of Human Population on Wildlife |date=9 June 2022 |publisher=Cambridge University Press |doi=10.1017/9781108985260 |isbn=978-1-108-98526-0|s2cid=249562874 }}</ref><ref>{{cite journal |last1= Ceballos|first1=Gerardo|last2=Ehrlich|first2=Paul R.|date=2023 |title=Mutilation of the tree of life via mass extinction of animal genera|url= |journal=]|volume=120 |issue=39 |pages=e2306987120|doi=10.1073/pnas.2306987120|pmid=37722053 |pmc=10523489 |bibcode=2023PNAS..12006987C |access-date=}}</ref> Many scientists have expressed concern about population growth, and argue that creating sustainable societies will require decreasing the current global population.<ref name="Ripple2017" /><ref name="Ripple-2019" /><ref name="Crist2022" /><ref>{{Cite journal |last1=Crist |first1=Eileen |last2=Kopnina |first2=Helen |last3=Cafaro |first3=Philip |last4=Gray |first4=Joe |last5=Ripple |first5=William J. |last6=Safina |first6=Carl |last7=Davis |first7=John |last8=DellaSala |first8=Dominick A. |last9=Noss |first9=Reed F. |last10=Washington |first10=Haydn |last11=Rolston |first11=Holmes |last12=Taylor |first12=Bron |last13=Orlikowska |first13=Ewa H. |last14=Heister |first14=Anja |last15=Lynn |first15=William S. |date=2021 |title=Protecting Half the Planet and Transforming Human Systems Are Complementary Goals |journal=Frontiers in Conservation Science |volume=2 |doi=10.3389/fcosc.2021.761292 |issn=2673-611X |quote=Population growth can end and numbers can be gradually lowered within a human-rights framework. Lowering human numbers is achievable by expanding and protecting human rights, especially for children and women . . . A smaller human population will facilitate the conservation of a biodiverse planet while also supporting a higher quality of life for people by lowering pollution levels, preempting resource conflicts, ameliorating overcrowding in urban centers, and empowering girls and women|doi-access=free }}</ref> Advocates have suggested implementation of ] to reach a proposed ].


<!--This paragraph summarises "Criticism" section. Please do not add caveats to it as it reflects section below.-->Overpopulation hypotheses are controversial, with many ] and environmentalists disputing the core premise that the world cannot sustain the current trajectory of human population.{{refn|name=Demographics-Environmentalists|<ref name="Piper-2019" /><ref name="Rao-1994" /><ref name="The Wire" /><ref name="Coole-2018">{{Cite book |last=Coole |first=Diana |url=http://worldcat.org/oclc/1162049054 |title=Should we control world population? |date=8 August 2018 |publisher=John Wiley & Sons |isbn=978-1-5095-2344-3 |oclc=1162049054}}</ref>}} Additionally, many ] and historians have noted that sustained ]s and ]s have historically been caused by war, ], political instability, and repressive political regimes (often employing ]) rather than overpopulation,{{refn|name=Economists–Historians1|<ref>{{cite book|last=Nove|first=Alec|author-link=Alexander Nove|year=1992|orig-year=1969|title=An Economic History of the USSR, 1917–1991|place=New York|publisher=]|edition=3rd|isbn=978-0140157741}}</ref><ref>{{cite book|last1=Schuettinger|first1=Robert|last2=Butler|first2=Eamonn|author-link2=Eamonn Butler|year=1979|title=Forty Centuries of Wage and Price Controls: How Not to Fight Inflation|place=Washington, DC|publisher=]|isbn=978-0891950257}}</ref><ref>{{cite book|last=Sen|first=Amartya|author-link=Amartya Sen|year=1982|orig-year=1981|title=Poverty and Famines: An Essay on Entitlement and Deprivation|place=], ]|publisher=]|edition=Reprint|isbn=978-0198284635|url=https://archive.org/details/povertyfamineses0000sena|url-access=registration}}</ref><ref>{{cite book|last=Rockoff|first=Hugh|year=2004|orig-year=1984|title=Drastic Measures: A History of Wage and Price Controls in the United States|place=], England|publisher=]|edition=Paperback|isbn=978-0521522038}}</ref><ref>{{cite book|last=Becker|first=Jasper|author-link=Jasper Becker|year=1998|orig-year=1997|title=Hungry Ghosts: Mao's Secret Famine|title-link=Hungry Ghosts: Mao's Secret Famine|place=New York|publisher=]|edition=2nd|isbn=978-0805056686}}</ref><ref>{{cite book|last1=Courtois|first1=Stéphane|author-link1=Stéphane Courtois|last2=Werth|first2=Nicolas|author-link2=Nicolas Werth|last3=Panné|first3=Jean-Louis|last4=Paczkowski|first4=Andrzej|author-link4=Andrzej Paczkowski|last5=Bartošek|first5=Karel|last6=Margolin|first6=Jean-Louis|author-link6=Jean-Louis Margolin|translator-last1=Murphy|translator-first1=Jonathan|translator-last2=Kramer|translator-first2=Mark|year=1999|orig-year=1997|title=The Black Book of Communism: Crimes, Terror, Repression|title-link=The Black Book of Communism|place=]|publisher=]|isbn=978-0674076082}}</ref><ref>{{cite book|last=Sen|first=Amartya|year=2001|orig-year=1999|title=Development As Freedom|place=Oxford, England|publisher=Oxford University Press|edition=2nd|isbn=978-0192893307|url-access=registration|url=https://archive.org/details/developmentasfre00sena}}</ref><ref>{{cite book|last1=Davies|first1=R. W.|author-link1=R. W. Davies|last2=Wheatcroft|first2=Stephen G.|author-link2=Stephen G. Wheatcroft|year=2004|title=The Years of Hunger: Soviet Agriculture, 1931–1933|place=], England|publisher=]|isbn=978-0230238558}}</ref><ref>{{cite book|last=Dikötter|first=Frank|author-link=Frank Dikötter|year=2017|orig-year=2010|title=Mao's Great Famine: The History of China's Most Devastating Catastrophe, 1958–1962|title-link=Mao's Great Famine|place=], England|publisher=]|isbn=978-1408886366}}</ref><ref>{{cite journal|last1=Hasell|first1=Joe|last2=Roser|first2=Max|author-link2=Max Roser|date=7 December 2017|title=Famines|journal=]|publisher=Global Change Data Lab|url=https://ourworldindata.org/famines|access-date=4 April 2023}}</ref>}} and that population growth ] has led to greater ] and ] that has enabled the ] of ]s and technology that better conserves and more efficiently uses natural resources, produces greater agricultural output with less land and less water, and addresses human impacts on the environment due to there being greater numbers of scientists, engineers, and ] and subsequent generations of scientists ] maintained by ].{{refn|name=Economists–Historians2|<ref>{{cite book|last1=Kuznets|first1=Simon|author-link1=Simon Kuznets|last2=Quandt|first2=Richard E.|author-link2=Richard E. Quandt|last3=Friedman|first3=Milton|author-link3=Milton Friedman|year=1960|title=Demographic and Economic Change in Developed Countries|chapter=Population Change and Aggregate Output|place=]|publisher=]|edition=Reprint|pages=324–351|isbn=978-0870143021|chapter-url=https://www.nber.org/system/files/chapters/c2392/c2392.pdf}}</ref><ref>{{cite book|last=Kuhn|first=Thomas|author-link=Thomas Kuhn|year=2012|orig-year=1962|title=The Structure of Scientific Revolutions|title-link=The Structure of Scientific Revolutions|place=], ]|publisher=]|edition=4th|isbn=978-0226458120}}</ref><ref>{{cite book|last=Simon|first=Julian L.|author-link=Julian Simon|year=2019|orig-year=1977|title=The Economics of Population Growth|place=Princeton, NJ|publisher=Princeton University Press|edition=Reprint|isbn=978-0691656298}}</ref><ref name="Simon 1981">{{cite book|last=Simon|first=Julian L.|year=1981|title=The Ultimate Resource|place=Princeton, NJ|publisher=Princeton University Press|isbn=069109389X|url=https://archive.org/details/ultimateresource00juli/|url-access=registration}}</ref><ref>{{cite journal|last=Kremer|first=Michael|author-link=Michael Kremer|year=1993|title=Population Growth and Technological Change: One Million B.C. to 1990|journal=]|place=]|publisher=]|volume=108|issue=3|pages=681–716|jstor=2118405|s2cid=139085606|doi=10.2307/2118405}}</ref><ref name="Simon 1996">{{cite book|last1=Simon|first1=Julian L.|year=1996|title=The Ultimate Resource 2|place=Princeton, NJ|publisher=Princeton University Press|isbn=0691042691|url=https://archive.org/details/ultimateresource00simo|url-access=registration}}</ref><ref>{{cite journal|last1=Ausubel|first1=Jesse H.|author-link1=Jesse H. Ausubel|last2=Wernick|first2=Iddo K.|last3=Waggoner|first3=Paul E.|title=Peak Farmland and the Prospect for Land Sparing|journal=]|volume=38|issue=s1|year=2013|pages=221–242|doi=10.1111/j.1728-4457.2013.00561.x|doi-access=free}}</ref><ref>{{cite web|last=Ritchie|first=Hannah|author-link=Hannah Ritchie|date=22 August 2017|title=Yields vs. Land Use: How the Green Revolution enabled us to feed a growing population|website=Our World in Data|publisher=Global Change Data Lab|url=https://ourworldindata.org/yields-vs-land-use-how-has-the-world-produced-enough-food-for-a-growing-population|access-date=9 March 2023}}</ref><ref>{{cite journal|last1=Ritchie|first1=Hannah|last2=Roser|first2=Max|year=2019|title=Land Use|journal=]|publisher=Global Change Data Lab|url=https://ourworldindata.org/land-use|access-date=4 April 2023}}</ref><ref>{{cite journal|last1=Azoulay|first1=Pierre|last2=Fons-Rosen|first2=Christian|last3=Graff Zivin|first3=Joshua S.|year=2019|title=Does Science Advance One Funeral at a Time?|journal=]|publisher=]|volume=109|issue=8|pages=2889–2920|doi=10.1257/aer.20161574|pmid=31656315|pmc=6814193}}</ref>}} Instead, ] about human overpopulation are over the ] (and often devolve into social scientists and biologists simply ]).{{refn|name=Economists–Historians3|<ref name="Simon 1981" /><ref name="Simon 1996" /><ref name="Nature 12-1-2015">{{Cite journal|last=Scudellari|first=Megan|date=1 December 2015|title=The science myths that will not die|journal=Nature|language=en|volume=528|issue=7582|pages=322–325|doi=10.1038/528322a|pmid=26672537|bibcode=2015Natur.528..322S|s2cid=1414926|issn=1476-4687|doi-access=free}}</ref>}}
==History of concern==
], ].]]
Concern about overpopulation is an ancient topic. ] was a resident of the city of ] in the second century ], when the population of the world was about 190 million (only 3–4% of what it is today). He notably said: "What most frequently meets our view (and occasions complaint) is our teeming population. Our numbers are burdensome to the world, which can hardly support us.... In very deed, pestilence, and famine, and wars, and earthquakes have to be regarded as a remedy for nations, as the means of pruning the luxuriance of the human race." Before that, ], ] and others broached the topic as well.<ref>Roberts, R.E. (1924). {{webarchive |url=https://web.archive.org/web/20160303212931/http://www.tertullian.org/articles/roberts_theology/roberts_05.htm |date=3 March 2016 }}. Tertullian.org (2001-07-14). Retrieved on 2012-08-29.</ref>


Annual world population growth peaked at 2.1% in 1968, has since dropped to 1.1%, and could drop even further to 0.1% by 2100.<ref name="OWOD2019">{{Cite journal|url=https://ourworldindata.org/world-population-growth-past-future|title=Two centuries of rapid global population growth will come to an end|last=Roser|first=Max|date=18 June 2019|journal=Our World in Data}}</ref> Based on this, the ] projects the world population, which is 7.8 billion {{as of|2020|lc=y}}, to level out around 2100 at 10.9 billion<ref>{{Cite web|url=https://population.un.org/wpp/Graphs/Probabilistic/POP/TOT/900|title=World Population Prospects 2019|date=2019|website=United Nations, Dept of Economic and Social Affairs}}</ref><ref name=":8b">{{Cite web|url=https://population.un.org/wpp/Download/Standard/Population/|title=World Population Prospects 2019, Population Data, File: Total Population Both Sexes, Medium Variant tab|date=2019|website=United Nations Population Division}}</ref><ref name=":1b">{{Cite web|url=https://population.un.org/wpp/Download/Standard/Fertility/|title=World Population Prospects 2019, Dept of Economic and Social Affairs, File: Total Fertility|date=2019|website=United Nations Population Division}}</ref> with other models proposing similar stabilization before or after 2100.<ref name="Roser-2013" /><ref name="Vollset-2020">{{Cite journal|last1=Vollset|first1=Stein Emil|last2=Goren|first2=Emily|last3=Yuan|first3=Chun-Wei|last4=Cao|first4=Jackie|last5=Smith|first5=Amanda E.|last6=Hsiao|first6=Thomas|last7=Bisignano|first7=Catherine|last8=Azhar|first8=Gulrez S.|last9=Castro|first9=Emma|last10=Chalek|first10=Julian|last11=Dolgert|first11=Andrew J.|date=17 October 2020|title=Fertility, mortality, migration, and population scenarios for 195 countries and territories from 2017 to 2100: a forecasting analysis for the Global Burden of Disease Study|journal=The Lancet|language=English|volume=396|issue=10258|pages=1285–1306|doi=10.1016/S0140-6736(20)30677-2|issn=0140-6736|pmc=7561721|pmid=32679112|doi-access=free}}</ref><ref name="Science">{{Cite journal|last1=Gerland|first1=P.|last2=Raftery|first2=A. E.|last3=Ev Ikova|first3=H.|last4=Li|first4=N.|last5=Gu|first5=D.|last6=Spoorenberg|first6=T.|last7=Alkema|first7=L.|last8=Fosdick|first8=B. K.|last9=Chunn|first9=J.|last10=Lalic|first10=N.|last11=Bay|first11=G.|date=14 September 2014|title=World population stabilization unlikely this century|journal=Science|publisher=AAAS|volume=346|issue=6206|pages=234–7|doi=10.1126/science.1257469|issn=1095-9203|pmc=4230924|pmid=25301627|last12=Buettner|first12=T.|last13=Heilig|first13=G. K.|last14=Wilmoth|first14=J.|bibcode=2014Sci...346..234G}}</ref> Some experts believe that a combination of factors (including technological and social change) would allow global resources to meet this increased demand, avoiding global overpopulation.<ref name="Our World in Data-2" /><ref name="Deutsche Welle" /> Additionally, some critics dismiss the idea of human overpopulation as a ] connected to attempts to blame environmental issues on overpopulation, oversimplify complex social or economic systems, or place blame on developing countries and poor populations—] or racist assumptions and leading to discriminatory policy.<ref name="Nature 12-1-2015" /><ref name="10.1080/01436597.2014.926110" /><ref>{{cite web|date=7 December 2009|title=The spectre of "overpopulation"|url=https://www.tni.org/en/article/the-spectre-of-overpopulation|access-date=13 March 2021|website=Transnational Institute|language=en}}</ref><ref name="Piper-2019">{{cite web|last=Piper|first=Kelsey|date=20 August 2019|title=We've worried about overpopulation for centuries. And we've always been wrong.|url=https://www.vox.com/future-perfect/2019/8/20/20802413/overpopulation-demographic-transition-population-explained|access-date=30 July 2021|website=Vox|language=en}}</ref> These critics often suggest ] should be treated as an issue separate from ].<ref name="Kaneda-2014" /><ref name="Pearce-2010">{{cite web|last=Pearce|first=Fred|date=8 March 2010|title=The Overpopulation Myth|url=https://www.prospectmagazine.co.uk/magazine/the-overpopulation-myth|website=]}}</ref>
Throughout history, population growth has usually been slow despite high ], due to war, ] and other diseases, and high ]. During the 750 years before the ], the world's population increased very slowly, remaining under 250 million.<ref>], ''Critical Masses: The Global Population Challenge'' (1994): " capped by birth rates and death rates locked in a seemingly permanent equilibrium."</ref>


===History of world population===
By the beginning of the 19th century, the world population had grown to a billion individuals, and intellectuals such as ] predicted that mankind would outgrow its available resources, because a finite amount of land would be incapable of supporting a population with a limitless potential for increase.<ref>{{cite book|title=An Essay on the Principle of Population|date=1798|publisher=J. Johnson,|location=London|chapter=VII, paragraph 10, lines 8–10|quote=The power of population is so superior to the power in the earth to produce subsistence for man, that premature death must in some shape or other visit the human race}}</ref> ] argued that a large population was a form of wealth, which made it possible to create bigger markets and armies.
{{main|World population milestones|}}


{{See also|Population growth||}}]
During the 19th century, Malthus's work was often interpreted in a way that blamed the poor alone for their condition and helping them was said to worsen conditions in the long run.<ref name="Claeys">Gregory Claeys: The "Survival of the Fittest" and the Origins of Social Darwinism, in: Journal of the History of Ideas, Vol. 61, No. 2, 2002, p. 223–240</ref> This resulted, for example, in the ] of 1834<ref name="Claeys"/> and in a hesitating response to the ] of 1845–52.<ref>Cormac Ó Gráda: Famine. A Short History, Princeton University Press 2009, {{ISBN|978-0-691-12237-3}} (pp. 20, 203–206)</ref>
] (See ''].'')|220x220px]]
]


] has been rising continuously since the end of the ], around the year 1350.<ref>{{cite web|url=http://www.abc.net.au/science/articles/2008/01/29/2149185.htm |title=Black death 'discriminated' between victims |website=] |access-date=3 November 2008 |url-status=live |archive-url=https://web.archive.org/web/20161220120404/http://www.abc.net.au/science/articles/2008/01/29/2149185.htm |archive-date=20 December 2016 |date=29 January 2008 }}</ref> The fastest doubling of the world population happened between 1950 and 1986: a doubling from 2.5 to 5 billion people in 37 years,<ref>{{Cite journal|last1=Roser|first1=Max|last2=Ritchie|first2=Hannah|last3=Ortiz-Ospina|first3=Esteban|date=9 May 2013|title=World Population Growth|url=https://ourworldindata.org/world-population-growth|journal=Our World in Data}}</ref> mainly due to ] and increases in ].<ref>Pimentel, David. "Overpopulation and sustainability." Petroleum Review 59 (2006): 34–36.</ref><ref>Hayami, Yujiro, and Vernon W. Ruttan. "Population growth and agricultural productivity." Technological Prospects and Population Trends. Routledge, 2020. 11–69.</ref> Due to its impact on the human ability to grow food, the ] enabled the global population to increase from 1.6 billion in 1900 to 7.7 billion by November 2018 and, according to the ], eight billion as of November 2022.<ref name="Smil 1999">{{cite journal|last1=Smil|first1=Vaclav|year=1999|title=Detonator of the population explosion|url=http://www.vaclavsmil.com/wp-content/uploads/docs/smil-article-1999-nature7.pdf|journal=Nature|volume=400|issue=6743|page=415|bibcode=1999Natur.400..415S|doi=10.1038/22672|s2cid=4301828}}</ref><ref>United Nations Department of Economic and Social Affairs, Population Division (2022). ''World Population Prospects 2022: Summary of Results''. UN DESA/POP/2022/TR/NO. 3, p. 1</ref> Some researchers have analyzed this growth in population like other animal populations, human populations predictably grow and shrink according to their available food supply as per the ], including ] and insect ecologist ],<ref name="Hopfenberg and Pimentel">Hopfenberg, Russell and Pimentel, David, "", ''Environment, Development and Sustainability'', vol. 3, no. 1, March 2001, pp. 1–15</ref> behavioral scientist Russell Hopfenberg,<ref>{{cite web|title=Human Carrying Capacity is Determined by Food Availability|url=http://www.populationmedia.org/wp-content/uploads/2010/03/Human-Carrying-Capacity-is-Determined-by-Food-Availability.pdf|work=Russel Hopfenberg, ]|publisher=Population media center|access-date=15 September 2020|archive-date=21 September 2020|archive-url=https://web.archive.org/web/20200921005240/http://www.populationmedia.org/wp-content/uploads/2010/03/Human-Carrying-Capacity-is-Determined-by-Food-Availability.pdf|url-status=dead}}</ref><ref>{{cite web|url=https://populationinstitutecanada.ca/wp-content/uploads/2020/08/Hopfenberg-A-Summary-of-Human-Population-Dynamics-2020.pdf|title=A Summary of Human Population Dynamics|last=Hopfenberg|first=Russel|publisher=Population institute of Canada}}</ref> and anthropologist ].<ref>Abernathy, Virginia, ''Population Politics'' {{ISBN|0-7658-0603-7}}</ref>
The UN Population Assessment Report of 2004 projects that the world population will plateau by 2050 and will remain stable until 2300.<ref>UN Department of Economic and Social Affairs: Population Division. World Population to 2300. {{cite web|url=https://www.un.org/esa/population/publications/longrange2/WorldPop2300final.pdf |title=Archived copy |accessdate=2016-05-24 |deadurl=no |archiveurl=https://web.archive.org/web/20161202044347/http://www.un.org/esa/population/publications/longrange2/WorldPop2300final.pdf |archivedate=2 December 2016 |df=dmy }}</ref> A 2014 study published in '']'' challenges this projection, asserting that population growth will continue into the next century.<ref>{{cite web|author=Carrington, Damien|date= September 18, 2014|url=https://www.theguardian.com/environment/2014/sep/18/world-population-new-study-11bn-2100 |title=World population to hit 11bn in 2100 – with 70% chance of continuous rise|work=The Guardian|accessdate= December 19, 2016}}</ref><ref>{{Cite journal | doi = 10.1126/science.1257469| pmid = 25301627| title = World population stabilization unlikely this century| journal = Science| volume = 346| issue = 6206| pages = 234–7| publisher = AAAS| date = September 18, 2014| url = | issn = 1095-9203| last1 = Gerland | first1 = P.| last2 = Raftery | first2 = A. E.| last3 = Ev Ikova | first3 = H.| last4 = Li | first4 = N.| last5 = Gu | first5 = D.| last6 = Spoorenberg | first6 = T.| last7 = Alkema | first7 = L.| last8 = Fosdick | first8 = B. K.| last9 = Chunn | first9 = J.| last10 = Lalic | first10 = N.| last11 = Bay | first11 = G.| last12 = Buettner | first12 = T.| last13 = Heilig | first13 = G. K.| last14 = Wilmoth | first14 = J.| accessdate = December 19, 2016 | pmc=4230924}}</ref> Adrian Raftery, a ] professor of statistics and sociology and one of the contributors to the study, says: "The consensus over the past 20 years or so was that world population, which is currently around 7 billion, would go up to 9 billion and level off or probably decline. We found there's a 70 percent probability the world population will not stabilize this century. Population, which had sort of fallen off the world's agenda, remains a very important issue."<ref> {{webarchive |url=https://web.archive.org/web/20161204155734/http://www.washington.edu/news/2014/09/18/world-population-to-keep-growing-this-century-hit-11-billion-by-2100/ |date=4 December 2016 }}. UWToday. September 18, 2014</ref> A more recent UN projection suggests the population could grow to as many as 15 billion by 2100.<ref name="15billion"/>


{| class="wikitable"
==Human population==
|+ World population history<ref>{{cite web|url=https://ourworldindata.org/grapher/population-since-1800?country=~OWID_WRL|title=World Population Growth|publisher=Our World in Data|year=2013|author=Max Roser|author2=Hannah Ritchie|author3=Esteban Ortiz-Ospina|archive-url=https://web.archive.org/web/20211122212559/https://ourworldindata.org/grapher/population-since-1800|archive-date=22 November 2021}}</ref><ref>{{cite web|url=https://population.un.org/wpp/Graphs/1_Demographic%20Profiles/World.pdf|title=World Population Prospects 2019, Volume II: Demographic Profiles|publisher=United Nations, Department of Economic and Social Affairs, Population Division|year=2019|archive-url=https://web.archive.org/web/20210713134040/https://population.un.org/wpp/Graphs/1_Demographic%20Profiles/World.pdf|archive-date=13 July 2021}}</ref><ref>{{cite web|url=https://data.worldbank.org/indicator/SP.POP.TOTL|title=Population, total|publisher=World Bank Open Data|archive-url=https://web.archive.org/web/20220103053016/https://data.worldbank.org/indicator/SP.POP.TOTL|archive-date=3 January 2022}}</ref>

===History of population growth===
{{main article|World population}}
].]]

{| class="wikitable" style="float:right;"
! colspan="4" style="text-align:center; background:#cfb;"| Population<ref name="bbc.co.uk"/>
|- |-
! Year
! style="background:#cfb;"| Year
! 1806 !! 1850 !! 1900 !! 1940 !! 1950 !! 1960 !! 1970 !! 1980 !! 1990 !! 2000 !! 2010 !! 2020
! style="background:#cfb;"| Billion
|- |-
! Billions
| style="text-align:left;"| 1804 || style="text-align:right;"| 1
| 1.01 || 1.28 || 1.65 || 2.33 || 2.53 || 3.03 || 3.68 || 4.43 || 5.28 || 6.11 || 6.92 || 7.76
|-
| style="text-align:left;"| 1927 || style="text-align:right;"| 2
|-
| style="text-align:left;"| 1959 || style="text-align:right;"| 3
|-
| style="text-align:left;"| 1974 || style="text-align:right;"| 4
|-
| style="text-align:left;"| 1987 || style="text-align:right;"| 5
|-
| style="text-align:left;"| 1999 || style="text-align:right;"| 6
|-
| style="text-align:left;"| 2011 || style="text-align:right;"| 7
|-
| style="text-align:left;"| 2020 || style="text-align:right;"| 7.7 (estimate)<ref>{{cite web|url=http://www.worldometers.info/world-population/|title=Current World Population|publisher=Worldometers|accessdate=2014-04-18}}</ref>
|} |}


The human population has gone through a number of periods of growth since the dawn of ] in the ] period, around 10,000 BCE. The beginning of civilization roughly coincides with the receding of ] following the end of the ].<ref>{{cite web|url=http://muller.lbl.gov/pages/iceagebook/history_of_climate.html|title=A Brief Introduction to the History of Climate|publisher=Lawrence Berkeley National Laboratories|accessdate=May 22, 2013}}</ref> World population has gone through a number of periods of growth since the dawn of ] in the ] period, around 10,000 BCE. The beginning of civilization roughly coincides with the receding of ] following the end of the ].<ref>{{cite web|url=http://muller.lbl.gov/pages/iceagebook/history_of_climate.html|title=A Brief Introduction to the History of Climate|publisher=Lawrence Berkeley National Laboratories|access-date=22 May 2013}}</ref> Farming allowed for the growth of populations in many parts of the world, including Europe, the Americas and China through the 1600s, occasionally disrupted by plagues or other crises.<ref>{{cite web |url=http://science.nationalgeographic.com/science/health-and-human-body/human-diseases/plague-article.html |archive-url=https://web.archive.org/web/20071128194106/http://science.nationalgeographic.com/science/health-and-human-body/human-diseases/plague-article.html |url-status=dead |archive-date=28 November 2007 |title=Plague, Plague Information, Black Death Facts, News, Photos |work=National Geographic |access-date=3 November 2008}}</ref><ref>"''''". J. N. Hays (2005). p.46. {{ISBN|1-85109-658-2}}</ref> For example, the Black Death is thought to have reduced the world's population, then at an estimated 450 million in 1350, to between 350 and 375 million by 1400.<ref>{{cite web |url=https://www.census.gov/ipc/www/worldhis.html |title=Historical Estimates of World Population |publisher=Census.gov |access-date=3 November 2008 |url-status=dead |archive-url=https://web.archive.org/web/20131013110506/http://www.census.gov/ipc/www/worldhis.html |archive-date=13 October 2013 }}</ref>
It is estimated that between 1–5 million people, subsisting on hunting and ], inhabited the Earth in the period before the ], when human activity shifted away from ] and towards ].<ref>{{cite web|url=http://msh.councilforeconed.org/documents/978-1-56183-758-8-activity-lesson-03.pdf|title=The Neolithic Agricultural Revolution|page=46|publisher=Council For Economic Education|accessdate=May 22, 2013}}</ref>


After the start of the ], during the 18th century, the rate of population growth began to increase. By the end of the century, the world's population was estimated at just under 1 billion.<ref name="censushistorical">{{cite web|title=International Programs|url=https://www.census.gov/ipc/www/worldhis.html|website=census.gov|url-status=dead|archive-url=https://web.archive.org/web/20131013110506/http://www.census.gov/ipc/www/worldhis.html|archive-date=13 October 2013}}</ref> At the turn of the 20th century, the world's population was roughly 1.6 billion.<ref name="censushistorical" /> By 1940, this figure had increased to 2.3 billion.<ref>{{cite web|title=modelling exponential growth|url=http://www.esrl.noaa.gov/gmd/infodata/lesson_plans/Modeling%20Exponential%20Growth.pdf|website=esrl.noaa.gov}}</ref> Even more dramatic growth beginning in 1950 (above 1.8% per year) coincided with greatly increased food production as a result of the industrialization of agriculture brought about by the ].<ref name="The limits of a Green Revolution">"". BBC News. 29 March 2007.</ref> The rate of human population growth peaked in 1964, at about 2.1% per year.<ref>{{cite web|title=United Nations, United Nations, Department of Economic and Social Affairs, Population Division (2011): World Population Prospects: The 2010 Revision|url=http://esa.un.org/unpd/wpp/Analytical-Figures/htm/fig_6.htm|url-status=bot: unknown|archive-url=https://web.archive.org/web/20110512065842/http://esa.un.org/unpd/wpp/Analytical-Figures/htm/fig_6.htm|archive-date=12 May 2011|access-date=25 September 2012}}</ref> Recent additions of a billion humans happened very quickly: 33 years to reach three billion in 1960, 14 years for four billion in 1974, 13 years for five billion in 1987, 12 years for six billion in 1999, 11 years for seven billion in 2010, and 12 years for 8 billion toward the end of 2022.<ref>{{cite book|last=Benatar|first=David|date=2008|title=Better Never to Have Been: The Harm of Coming into Existence|url=https://archive.org/details/betternevertohav0000bena/page/167|publisher=]|page=|isbn=978-0199549269|author-link=David Benatar}}</ref><ref>{{cite report |url=https://www.un.org/development/desa/pd/sites/www.un.org.development.desa.pd/files/wpp2022_summary_of_results.pdf |title=World Population Prospects 2022: Summary of Results |date=2022 |publisher=United Nations Department of Economic and Social Affairs, Population Division |page= |id=UN DESA/POP/2022/TR/NO.3}}</ref>
Around 8000 BCE, at the ], the population of the world was approximately 5 million.<ref name=worldometer>"What was the population of the world in the past?", </ref> The next several millennia saw a steady increase in the population, with very rapid growth beginning in 1000 BCE, and a peak of between 200 and 300 million people in 1 BCE.


].'')]]
The ] caused ] to drop by around 50% between 541 and the 8th century.<ref>{{cite web |url=http://science.nationalgeographic.com/science/health-and-human-body/human-diseases/plague-article.html |title=Plague, Plague Information, Black Death Facts, News, Photos |publisher=National Geographic |accessdate=3 November 2008}}</ref> Steady growth resumed in 800 CE.<ref>"''''". J. N. Hays (2005). p.46. {{ISBN|1-85109-658-2}}</ref> However, growth was again disrupted by frequent ]; most notably, the ] during the 14th century. The effects of the Black Death are thought to have reduced the world's population, then at an estimated 450 million, to between 350 and 375 million by 1400.<ref>{{cite web|url=http://www.census.gov/ipc/www/worldhis.html |title=Historical Estimates of World Population |publisher=Census.gov |accessdate=3 November 2008}}</ref> The population of Europe stood at over 70 million in 1340;<ref>"". Encyclopædia Britannica.</ref> these levels did not return until 200 years later.<ref>"". TIME Europe. 17 July 2000, VOL. 156 NO. 3</ref> England's population reached an estimated 5.6 million in 1650, up from an estimated 2.6 million in 1500.<ref>"". Encyclopædia Britannica.</ref> New crops from the Americas via the Spanish colonizers in the 16th century contributed to the population growth.<ref>"". Columbia University, East Asian Curriculum Project.</ref>

In other parts of the globe, China's population at the founding of the ] in 1368 stood close to 60 million, approaching 150 million by the end of the dynasty in 1644.<ref>{{cite web|url=http://encarta.msn.com/encyclopedia_761580643/ming_dynasty.html |title=Ming Dynasty: Microsoft Encarta Online Encyclopedia 2009 |accessdate=2010-08-15 |deadurl=bot: unknown |archiveurl=https://web.archive.org/web/20090126181206/http://encarta.msn.com/encyclopedia_761580643/ming_dynasty.html |archivedate=26 January 2009 |df=dmy-all }}</ref><ref>"". Asia for Educators, Columbia University.</ref> The population of the Americas in 1500 may have been between 50 and 100 million.<ref>J. N. Hays (1998). "''''". p 72. {{ISBN|0-8135-2528-4}}</ref>

Encounters between European explorers and populations in the rest of the world often introduced local ] of extraordinary virulence. Archaeological evidence indicates that the death of around 90% of the ] of the ] was caused by ] diseases such as ], measles, and influenza.<ref>"". Public Broadcasting Service (PBS).</ref> Europeans introduced diseases alien to the indigenous people, therefore they did not have immunity to these foreign diseases.<ref>" {{webarchive|url=https://web.archive.org/web/20080510163413/http://www.millersville.edu/~columbus/papers/goodling.html |date=10 May 2008 }}"</ref>

After the start of the ], during the 18th century, the rate of population growth began to increase. By the end of the century, the world's population was estimated at just under 1 billion.<ref name=censushistorical>{{cite web|title=International Programs|url=http://www.census.gov/ipc/www/worldhis.html|website=http://www.census.gov}}</ref> At the turn of the 20th century, the world's population was roughly 1.6 billion.<ref name=censushistorical/> By 1940, this figure had increased to 2.3 billion.<ref>{{cite web|title=modelling exponential growth|url=http://www.esrl.noaa.gov/gmd/infodata/lesson_plans/Modeling%20Exponential%20Growth.pdf|website=http://www.esrl.noaa.gov/}}</ref>
{| class="wikitable" style="float: right; margin-left: 10px"
! colspan="2" style="text-align:center; background:#cfb;"| Population growth 1990–2009 (%)<ref name=IEAco-2011>{{cite web|title=CO2 EMISSIONS FROM FUEL COMBUSTION I E A S T A T I S T I C S International Energy Agency H I G H L I G H T S|url=http://www.iea.org/co2highlights/co2Highlights.pdf|website=http://www.iea.org}}</ref>
|-
| style="text-align:left;"| World || style="text-align:right;"| 28.4%
|-
| style="text-align:left;"| Africa || style="text-align:right;"| 58.4%
|-
| style="text-align:left;"| Middle East || style="text-align:right;"| 53.4%
|-
| style="text-align:left;"| Asia (except China) || style="text-align:right;"| 36.9%
|-
| style="text-align:left;"| Latin America || style="text-align:right;"| 32.0%
|-
| style="text-align:left;"| ] North America || style="text-align:right;"| 25.1%
|-
| style="text-align:left;"| China || style="text-align:right;"| 17.3%
|-
| style="text-align:left;"| OECD Europe || style="text-align:right;"| 9.9%
|-
| style="text-align:left;"| OECD Pacific || style="text-align:right;"| 9.5%
|-
| style="text-align:left;"| Non-OECD Europe and Eurasia|| style="text-align:right;"| -2.7%
|}
Dramatic growth beginning in 1950 (above 1.8% per year) coincided with greatly increased food production as a result of the industrialization of agriculture brought about by the ].<ref name="The limits of a Green Revolution">"". BBC News. 29 March 2007.</ref> The rate of human population growth peaked in 1964, at about 2.1% per year.<ref>{{cite web|url=http://esa.un.org/unpd/wpp/Analytical-Figures/htm/fig_6.htm |title=United Nations, United Nations, Department of Economic and Social Affairs, Population Division (2011): World Population Prospects: The 2010 Revision |accessdate=2012-09-25 |deadurl=bot: unknown |archiveurl=https://web.archive.org/web/20110512065842/http://esa.un.org/unpd/wpp/Analytical-Figures/htm/fig_6.htm |archivedate=12 May 2011 |df=dmy-all }}</ref> For example, ]'s population grew from 97 million in 1961 to 237.6 million in 2010,<ref>{{Cite news|author=Widjojo Nitisastro |url=https://books.google.com/books?id=RQbd3-G6riUC&pg=&dq&hl=en#v=onepage&q=&f=false |title= Population Trends in Indonesia|publisher= Equinox Publishing|accessdate=6 November 2011 | year=2006 |page=268 |isbn= 979-3780-43-6}}</ref><ref>{{cite web|url=http://www.bps.go.id/65tahun/SP2010_agregat_data_perProvinsi.pdf |title=Central Bureau of Statistics: ''Census 2010'' |publisher=Badan Pusat Statistik |accessdate=17 January 2011 |language=id |deadurl=yes |archiveurl=https://web.archive.org/web/20101113144717/http://www.bps.go.id/65tahun/SP2010_agregat_data_perProvinsi.pdf |archivedate=13 November 2010 |df=dmy-all }}</ref> a 145% increase in 49 years. In ], the population grew from 361.1 million people in 1951 to just over 1.2 billion by 2011,<ref>{{cite web|url=http://indiabudget.nic.in/es2006-07/chapt2007/tab97.pdf|title=Census Population|work=Census of India|publisher=Ministry of Finance India|accessdate=18 December 2008|format=PDF}}</ref><ref>{{Cite journal|year=2011|title=Provisional Population Totals – Census 2011|work=Office of the Registrar General and Census Commissioner|publisher=], Government of India|url=http://www.censusindia.gov.in/2011-prov-results/indiaatglance.html|accessdate=29 March 2011|ref={{Sfnref|Ministry of Home Affairs|2011}}}}</ref> a 235% increase in 60 years.


=== Future projections ===
{| class="wikitable" style="float:right;" {| class="wikitable" style="float:right;"
|- |-
! Continent !! Projected 2050 population
! Continent !! 1900 population<ref>"" (PDF). Population Reference Bureau (PRB).</ref>
by UN in 2017<ref>{{cite web|year=2017|title=World Population Prospects: The 2017 Revision|url=https://www.compassion.com/multimedia/world-population-prospects.pdf|url-status=dead|archive-url=https://web.archive.org/web/20181203060019/https://www.compassion.com/multimedia/world-population-prospects.pdf|archive-date=3 December 2018|access-date=2 December 2018|publisher=United Nations, Department of Economic and Social Affairs, Population Division}}</ref>
|- |-
| ]|| 2.5 billion
| Africa || 133 million
|- |-
| ]|| 5.5 billion
| Asia || 904 million
|- |-
| Europe || 408 million | ]|| 716 million
|- |-
| Latin America and Caribbean || 74 million | ] and ]|| 780 million
|- |-
| North America || 82 million | ]|| 435 million
|} |}
{{Main|Projections of population growth}}
'''Population projections''' are attempts to show how the ] might change in the future.<ref>{{Cite web|url=https://www.census.gov/programs-surveys/popproj.html|title=Population Projections|website=United States Census Bureau}}</ref> These projections help to ] the population's impact on this planet and humanity's future well-being.<ref>{{Cite web|last=Kaneda|first=Toshiko|date=June 2014|title=Understanding Population Projections: Assumptions Behind the Numbers|url=https://assets.prb.org/pdf14/understanding-population-projections.pdf|website=Population Reference Bureau}}</ref> Models of population growth take trends in ], and apply projections into the future<ref name=":311">{{Cite journal|last=Roser|first=Max|date=9 May 2013|title=Future Population Growth|url=https://ourworldindata.org/future-population-growth|journal=Our World in Data}}</ref> to understand how they will affect ] and ], and thus ].<ref name=":311" />


The most recent report from the ] issued in 2022 (see chart) projects that global population will peak around the year 2086 at about 10.4 billion, and then start a slow decline (the median line on the chart).&nbsp; As with earlier projections, this version assumes that the global average ] will continue to fall, but even further from 2.5 births per woman during the 2015–2020 period to 1.8 by the year 2100.<ref name="United Nations Department of Economic and Social Affairs, Population Division-2022">{{cite report|title= World Population Prospects 2022: Summary of Results |publisher= United Nations Department of Economic and Social Affairs, Population Division |id = UN DESA/POP/2022/TR/NO.3 |date=2022 |page = 28| url = https://www.un.org/development/desa/pd/sites/www.un.org.development.desa.pd/files/wpp2022_summary_of_results.pdf}}</ref>
There is concern over the sharp population increase in many countries, especially in ], that has occurred over the last several decades, and that it is creating problems with land management, natural resources and access to water supplies.<ref>{{cite web|url = http://web.mit.edu/africantech/www/articles/EnvChall.htm|title = The Environmental Challenges In Sub Saharan Africa|author = Akin L. Mabogunje|publisher = African Technology Forum|date = May 4, 1995|accessdate = May 22, 2013|authorlink = Akin Mabogunje}}</ref>
]
However, other estimates predict additional downward pressure on fertility (such as more education and family planning) which could result in peak population during the 2060–2070 period rather than later.<ref name="Roser-2013" /><ref name="Vollset-2020" />


According to the UN, of the predicted growth in world population between 2020 and 2050, all of that change will come from ], and more than half will come from just 8 African countries.<ref name="United Nations Department of Economic and Social Affairs, Population Division-2022" /> It is predicted that the population of sub-Saharan Africa will double by 2050.<ref>{{Cite web |last=Nations |first=United |title=Population |url=https://www.un.org/en/global-issues/population |access-date=8 May 2023 |website=United Nations |language=en}}</ref> The Pew Research Center predicts that 50% of births in the year 2100 will be in Africa.<ref>{{Cite web |title=World population growth is expected to nearly stop by 2100 |url=https://www.pewresearch.org/short-reads/2019/06/17/worlds-population-is-projected-to-nearly-stop-growing-by-the-end-of-the-century/ |access-date=8 May 2023 |website=Pew Research Center |language=en-US}}</ref> As an example of uneven prospects, the UN projects that ] will gain about 340 million people, about the present population of the US, to become the 3rd most populous country, and ] will lose almost half of its population.<ref name="United Nations Department of Economic and Social Affairs, Population Division-2022" />
The population of ] has, for example, grown from 6,279,921 in 1993 to 10,329,208 in 2009.<ref name=cia>{{cite web
|url = https://www.cia.gov/library/publications/the-world-factbook/geos/fk.html
|title = Falkland Islands (Islas Malvinas)
|publisher=CIA
|accessdate =5 March 2010}}</ref> ], ], ], ], ] and the ] are witnessing a similar growth in population. The situation is most acute in western, central and eastern Africa.<ref name="cliodynamics.ru"/> Refugees from places like ] have further strained the resources of neighboring states like Chad and Egypt. Chad is also host to roughly 255,000 ]s from Sudan's ] region, and about 77,000 refugees from the ], while approximately 188,000 Chadians have been displaced by their own civil war and famines, have either fled to either the Sudan, the Niger or, more recently, ].<ref>{{cite web|url=http://www.wfp.org/content/protracted-relief-and-recovery-operation-chad|title=Protracted Relief and Recovery Operation – Chad|publisher=World Food Program|accessdate=May 22, 2013}}</ref>


==History of overpopulation hypotheses==
===Projections of population growth===
{{Expand section|date=March 2021}}
{{main article|Projections of population growth}}
{| class="wikitable" style="float:right;"
|-
! Continent !! Projected 2050 population<ref>{{cite web|url=https://www.un.org/esa/population/publications/sixbillion/sixbilpart1.pdf |title=UN report – 2004 data |format=PDF |deadurl=yes |archiveurl=https://web.archive.org/web/20160101220025/http://www.un.org/esa/population/publications/sixbillion/sixbilpart1.pdf |archivedate=1 January 2016 |df=dmy-all }}</ref>
|-
| Africa || 1.8 billion
|-
| Asia || 5.3 billion
|-
| Europe || 628 million
|-
| Latin America and Caribbean || 809 million
|-
| North America || 392 million
|}
According to projections, the world population will continue to grow until at least 2050, with the population reaching 9 billion in 2040,<ref>{{cite web|url=http://www.worldometers.info/population/ |title=World Population Clock – Worldometers |publisher=Worldometers.info |accessdate=2011-11-30}}</ref><ref>{{cite web|url=http://www.census.gov/ipc/www/idb/worldpopinfo.php |title=International Data Base (IDB) – World Population |publisher=Census.gov |accessdate=2011-11-30}}</ref> and some ] putting the population as high as 11 billion in 2050.<ref>{{cite web|url=http://esa.un.org/unpp/ |title=Archived copy |accessdate=2009-12-04 |deadurl=yes |archiveurl=https://web.archive.org/web/20110429173209/http://esa.un.org/unpp/ |archivedate=29 April 2011 |df=dmy-all }}</ref> By 2100, the population could reach 15 billion.<ref name="15billion">{{cite web |url= https://www.theguardian.com/world/2011/oct/22/population-world-15bn-2100|title= Population of world 'could grow to 15bn by 2100' |first= Paul |last= Harris|date= October 22, 2011|work= ] |accessdate=August 31, 2016}}</ref> ] projected in the 1950s that world population would reach a peak of about nine billion, in the 21st century, and then stop growing, after a readjustment of the ] and a sanitation of the tropics.<ref>]: Wie werden wir leben? (''"How are we going to live?"'') Econ publishers, Munich 1954</ref>


=== Historical use ===
In 2000, the ] estimated that the world's population was growing at the rate of 1.14% (or about 75 million people) per year and according to data from the CIA's ], the world human population currently increases by 145 every minute.<ref>{{cite web|url=https://www.cia.gov/library/publications/the-world-factbook/geos/xx.html|title=People and Society:WORLD:Population growth rate|accessdate=4 March 2012|work=The World Factbook}}</ref>
{{See also|Malthusianism}}
Concerns about population size or density have a long history: ], a resident of the city of ] in the second century ], criticized population at the time: "Our numbers are burdensome to the world, which can hardly support us... In very deed, pestilence, and famine, and wars, and earthquakes have to be regarded as a remedy for nations, as the means of pruning the luxuriance of the human race."<ref>{{cite web|title=Population explosion is over|url=https://www.thejakartapost.com/academia/2020/02/29/population-explosion-is-over.html|access-date=22 October 2021|website=The Jakarta Post|language=en}}</ref> Despite those concerns, scholars have not found historic ] because of overpopulation or overconsumption.<ref>{{cite journal|author=Joseph A. Tainter|title=Archaeology of Overshoot and Collapse|doi=10.1146/annurev.anthro.35.081705.123136|journal=Annual Review of Anthropology|pages=59–74|volume=35|date=2006}}</ref>
]'' (1826) by ], which would go on to be an influential text on ]]]
By the early 19th century, intellectuals such as ] predicted that humankind would outgrow its available resources because a finite amount of land would be incapable of supporting a population with limitless potential for increase.<ref>{{cite book|title=An Essay on the Principle of Population|chapter-url=https://archive.org/details/in.ernet.dli.2015.228746|date=1798|publisher=J. Johnson|location=London|chapter=VII, paragraph 10, lines 8–10|quote=The power of population is so superior to the power in the earth to produce subsistence for man, that premature death must in some shape or other visit the human race}}</ref> During the 19th century, Malthus' work, particularly ''],'' was often interpreted in a way that blamed the poor alone for their condition and helping them was said to worsen conditions in the long run.<ref name="Claeys">Gregory Claeys: The "Survival of the Fittest" and the Origins of Social Darwinism, in Journal of the History of Ideas, Vol. 61, No. 2, 2002, p. 223–240</ref> This resulted, for example, in the ] of 1834<ref name="Claeys" /> and a hesitating response to the ] of 1845–52.<ref>Cormac Ó Gráda: Famine. A Short History, Princeton University Press 2009, {{ISBN|978-0-691-12237-3}} (pp. 20, 203–206)</ref>


The first ] was held in 1927 in Geneva, organized by the ] and ].<ref>{{Cite journal|last=Carr-Saunders|first=A. M.|date=1927|title=The Population Conference at Geneva|url=https://www.jstor.org/stable/2223628|journal=The Economic Journal|volume=37|issue=148|pages=670–672|doi=10.2307/2223628|jstor=2223628|issn=0013-0133}}</ref><ref>{{Cite journal|last=C. -S.|first=A. M.|date=1 October 1927|title=The World Population Conference|journal=Nature|language=en|volume=120|issue=3022|pages=465–466|doi=10.1038/120465a0|bibcode=1927Natur.120..465C|s2cid=4138206|issn=1476-4687|pmc=1567312}}</ref><ref>{{Cite journal|last=Connelly|first=Matthew|date=November 2006|title=To inherit the Earth. Imagining world population, from the yellow peril to the population bomb|url=https://www.cambridge.org/core/journals/journal-of-global-history/article/abs/to-inherit-the-earth-imagining-world-population-from-the-yellow-peril-to-the-population-bomb/8493BC475B75BE069796C3094B5A6838|journal=Journal of Global History|language=en|volume=1|issue=3|pages=299–319|doi=10.1017/S1740022806003019|s2cid=154909241 |issn=1740-0236}}</ref>
According to the United Nations' World Population Prospects report:<ref>{{cite web|url=https://www.un.org/popin/ |title=World Population Prospects |publisher=United Nations |accessdate=2011-11-30}}</ref>
]


=== Contemporary use ===
* The ] is currently growing by approximately 74 million people per year. Current United Nations predictions estimate that the world population will reach 9.0 billion around 2050, assuming a decrease in average ] from 2.5 down to 2.0.<ref name=UNPop>{{cite web|title=UN homepage|url=https://www.un.org/esa/population/unpop.htm|website=https://www.un.org/}}</ref><ref>{{cite book|year=2004|url=https://www.un.org/esa/population/publications/longrange2/WorldPop2300final.pdf |title=WORLD POPULATION TO 2300|publisher=United Nations|format=PDF |accessdate=2011-11-30}}</ref>
]'s book '']'' became a bestseller upon its release in 1968 and created renewed interest in overpopulation. The book predicted population growth would lead to ], ], and other social, environmental and economic strife in the coming decades, and advocated for policies to curb it.<ref name="Ehrlich-1990" /><ref name="Piper-2019" /><ref name="archive.is-2020-2" /> The ] published the influential report '']'' in 1972, which used computer modeling to similarly argue that continued population growth trends would lead to global system collapse.<ref name="Webb">{{cite web|last=Webb|first=Richard|title=The population debate: Are there too many people on the planet?|url=https://www.newscientist.com/article/mg24833080-800-the-population-debate-are-there-too-many-people-on-the-planet/|url-status=live|archive-url=https://web.archive.org/web/20201111125807/https://www.newscientist.com/article/mg24833080-800-the-population-debate-are-there-too-many-people-on-the-planet/|archive-date=11 November 2020|access-date=21 October 2021|website=New Scientist|language=en-US}} {{Webarchive|url=https://web.archive.org/web/20211021103950/https://pages.stolaf.edu/2017-bies-228/wp-content/uploads/sites/1061/2021/01/The-Population-Debate-New-Scientist-11.2020.pdf |date=21 October 2021 }}</ref> The idea of overpopulation was also a topic of some works of English-language ] and ] during the latter part of the 1960s.<ref name="archive.is-2020-2">{{cite news|date=8 January 2020|title=The Unrealized Horrors of Population Explosion – The New York Times|url=https://www.nytimes.com/2015/06/01/us/the-unrealized-horrors-of-population-explosion.html|archive-url=https://archive.today/20200108123334/https://www.nytimes.com/2015/06/01/us/the-unrealized-horrors-of-population-explosion.html|url-status=dead|archive-date=8 January 2020|access-date=5 August 2021|website=archive.is}}</ref> The ] held the first of three ] in 1974.<ref>{{cite web|title=United Nations Population Division {{!}} Department of Economic and Social Affairs|url=https://www.un.org/en/development/desa/population/events/conference/index.asp|access-date=11 February 2022|website=www.un.org|language=EN}}</ref> ] and ] policies were adopted by some nations in the late 20th century in an effort to curb population growth, including in ] and ].<ref name="Roser-2013" /> ] gave more than 1,742 lectures on the threat of exponential population growth starting in 1969.<ref name="Nature 12-1-2015" />
* Almost all growth will take place in the less developed regions, where today's 5.3 billion population of underdeveloped countries is expected to increase to 7.8 billion in 2050. By contrast, the population of the more developed regions will remain mostly unchanged, at 1.2 billion. An exception is the United States population, which is expected to increase by 44% from 2008 to 2050.<ref>{{cite web|url=http://www.census.gov/ |title=US Census Bureau estimates and news release.of AUG. 14, 2008 |publisher=Census.gov |accessdate=2011-11-30}}</ref>
] generated renewed interest in the topic of overpopulation with '']'' (1968).]]
* In 2000–2005, the average world fertility was 2.65 children per woman, about half the level in 1950–1955 (5 children per woman). In the medium variant, global fertility is projected to decline further to 2.05 children per woman.
However, many predictions of overpopulation during the 20th century did not materialize.<ref name="archive.is-2020-2" /><ref name="Piper-2019" /> In '']'', Ehrlich stated, "In the 1970s hundreds of millions of people will starve to death in spite of any crash programs embarked upon now,"<ref name="leaders">{{Cite book|url=https://books.google.com/books?id=oHYD-XUiSBEC&pg=PA318|title=Leaders from the 1960s: A Biographical Sourcebook of American Activism|publisher=Greenwood Press, 1994|year=1994|isbn=9780313274145|page=318}}</ref> with later editions changing to "in the 1980s".<ref name="Scientific American" /> Despite admitting some of his earlier predictions did not come to pass, Ehrlich continues to advocate that overpopulation is a major issue.<ref name="archive.is-2020-2" />
* During 2005–2050, nine countries are expected to account for half of the world's projected population increase: ], Pakistan, ], Democratic Republic of the Congo, ], Uganda, United States, Ethiopia, and China, listed according to the size of their contribution to population growth. China would be higher still in this list were it not for its ].
* Global life expectancy at birth is expected to continue rising from 65 years in 2000–2005 to 75 years in 2045–2050. In the more developed regions, the projection is to 82 years by 2050. Among the least developed countries, where life expectancy today is just under 50 years, it is expected to increase to 66 years by 2045–2050.
* The population of 51 countries or areas is expected to be lower in 2050 than in 2005.
* During 2005–2050, the net number of international migrants to more developed regions is projected to be 98 million. Because deaths are projected to exceed births in the more developed regions by 73 million during 2005–2050, population growth in those regions will largely be due to international migration.
* In 2000–2005, net migration in 28 countries either prevented ] or doubled at least the contribution of natural increase (births minus deaths) to population growth.
* ]s are now falling in a small percentage of ], while the actual populations in many ] would fall without immigration.<ref name=UNPop/>


As the ] of ] facing humanity increased during the end of the 20th and the early 21st centuries, some have looked to population growth as a root cause. In the 2000s, ] and Ron Nielsen discussed overpopulation as a threat to the quality of human life.<ref name="wilson">Wilson, E.O. (2002). ''The Future of Life''. pp. xxiii, 39, 43, 76. Vintage {{ISBN|0-679-76811-4}}</ref><ref name="Nielsen" />{{rp|37–39}}{{Primary source inline|date=July 2022}} In 2011, ] argued that human overpopulation represents a threat to Earth's ].<ref>Pentti Linkola, "Can Life Prevail?", Arktos Media, 2nd Revised ed. 2011. pp. 120–121. {{ISBN|1907166637}}</ref>{{Primary source inline|date=July 2022}} A 2015 survey from ] reports that 82% of scientists associated with the ] were concerned about population growth.<ref name="Pew2015">{{cite news |last=Gao |first=George |date=8 June 2015 |title=Scientists more worried than public about world's growing population |url=https://www.pewresearch.org/fact-tank/2015/06/08/scientists-more-worried-than-public-about-worlds-growing-population/ |work=] |location= |access-date=6 October 2021}}</ref> In 2017, more than one-third of ] surveyed by the '']'' at the ] said that human overpopulation and ] are the two greatest threats facing mankind.<ref name="Moody2017">{{cite news |last= Moody|first=Oliver|date=31 August 2017 |title=Overpopulation is the biggest threat to mankind, Nobel laureates say|url=https://www.thetimes.co.uk/article/overpopulation-is-the-biggest-threat-to-mankind-nobel-laureates-say-zxdnv2bcv|work=]|access-date= 2 September 2017}}</ref> In November that same year, the ], signed by 15,364 scientists from 184 countries, indicated that rapid human population growth is "a primary driver behind many ecological and even societal threats."<ref name="Ripple2017">{{cite journal|vauthors=Ripple WJ, Wolf C, Newsome TM, Galetti M, Alamgir M, Crist E, Mahmoud MI, Laurance WF|title=World Scientists' Warning to Humanity: A Second Notice|journal=]|date=13 November 2017|volume=67|issue=12|pages=1026–1028|doi=10.1093/biosci/bix125|url=http://scientistswarning.forestry.oregonstate.edu/sites/sw/files/Warning_article_with_supp_11-13-17.pdf|doi-access=free|access-date=12 July 2018|archive-date=15 December 2019|archive-url=https://web.archive.org/web/20191215010626/https://scientistswarning.forestry.oregonstate.edu/sites/sw/files/Warning_article_with_supp_11-13-17.pdf|url-status=dead}}</ref> Ehlrich and other scientists at a conference in the Vatican on ] linked the issue to population growth in 2017, and advocated for ], which attracted controversy from the ].<ref>{{cite news|last=McKie|first=Robin|date=25 January 2017|title=Biologists think 50% of species will be facing extinction by the end of the century|work=The Observer|url=https://www.theguardian.com/environment/2017/feb/25/half-all-species-extinct-end-century-vatican-conference}}</ref> In 2019, a warning on ] signed by 11,000 scientists from 153 nations said that human population growth adds 80 million humans annually, and "the world population must be stabilized—and, ideally, gradually reduced—within a framework that ensures social integrity" to reduce the impact of "population growth on GHG emissions and biodiversity loss."<ref name="Ripple-2019">{{cite journal |last1= Ripple |first1=William J.|last2=Wolf|first2=Christopher |last3= Newsome |first3=Thomas M |last4=Barnard |first4= Phoebe |last5= Moomaw |first5=William R |date=5 November 2019 |title=World Scientists' Warning of a Climate Emergency |url=https://academic.oup.com/bioscience/advance-article/doi/10.1093/biosci/biz088/5610806 |journal=] |doi=10.1093/biosci/biz088 |access-date=8 November 2019|author-link1=William J. Ripple|hdl=1808/30278 |hdl-access=free }}</ref><ref>{{cite news |last= Carrington |first=Damian |date=5 November 2019 |title=Climate crisis: 11,000 scientists warn of 'untold suffering'|url=https://www.theguardian.com/environment/2019/nov/05/climate-crisis-11000-scientists-warn-of-untold-suffering |work=] |access-date=8 November 2019}}</ref>
===Urban growth===
]
In 1800 only 3% of the ] lived in cities. By the 20th century's close, 47% did so. In 1950 there were 83 cities with populations exceeding one million; but by 2007 this had risen to 468 agglomerations of more than one million.<ref>{{cite web|url=http://www.citypopulation.de/World.html |title=Principal Agglomerations of the World |publisher=Citypopulation.de |accessdate=2011-11-30}}</ref> If the trend continues, the world's ] will double every 38 years, according to researchers. The UN forecasts that today's urban population of 3.2 billion will rise to nearly 5 billion by 2030, when three out of five people will live in cities.<ref>{{cite news|url=http://www.forbes.com/2007/06/11/megacities-population-urbanization-biz-cx_21cities_ml_0611megacities.html |title=Megacities Of The Future |work=Forbes |accessdate=2011-11-30 |date=2007-06-11 |first=Mark |last=Lewis}}</ref>


In 2020, a quote from ] about how humans have "overrun the planet" was shared widely online and became his most popular comment on the internet.<ref name="www.newstatesman.com-2020" />
The increase will be most dramatic in the poorest and least-urbanised continents, Asia and Africa. Projections indicate that most urban growth over the next 25 years will be in ].<ref>{{cite web|title=Nigeria: Lagos, the mega-city of slums |url=http://www.energypublisher.com/article.asp?id=5307 |website=https://web.archive.org/web/20110218170316/http://www.energypublisher.com/ |deadurl=yes |archiveurl=https://web.archive.org/web/20110218170316/http://www.energypublisher.com/article.asp?id=5307 |archivedate=18 February 2011 }}</ref> One billion people, one-seventh of the world's population, or one-third of urban population, now live in ],<ref>{{cite news|last=Whitehouse |first=David |url=http://news.bbc.co.uk/2/hi/science/nature/4561183.stm |title=Half of humanity set to go urban |publisher=BBC News |date=2005-05-19 |accessdate=2011-11-30}}</ref> which are seen as "breeding grounds" for social problems such as unemployment, poverty, crime, ], alcoholism, and other social ills.<ref name=Ehrlich-Books>] and Anne Ehrlich, '']'' (1968), ''The Population Explosion'' (1990), ''The Population Bomb'' (1995) reprint, ''One With Nineveh: Politics, Consumption, and the Human Future'' (2004), ''The Dominant Animal: Human Evolution and the Environment'' (2008), ''Humanity on a Tightrope'' (2010, with ])</ref> In many poor countries, ] exhibit high rates of disease due to unsanitary conditions, malnutrition, and lack of basic health care.<ref>{{cite web|url=http://www.blackcommentator.com/88/88_reprint_planet_slums.html |title=Planet of Slums – The Third World's Megacities |publisher=Blackcommentator.com |accessdate=2011-11-30}}</ref>


==Key arguments==
In 2000, there were 18 ]{{snd}}]s such as Tokyo, ], ], ], ], Mexico City, ], São Paulo, London and New York City{{snd}}that have populations in excess of 10 million inhabitants. ] already has 35 million, more than the entire population of Canada (at 34.1 million).<ref>{{cite news|url=http://www.economist.com/surveys/displaystory.cfm?story_id=9070726 |title=The world goes to town |work=The Economist |accessdate=2011-11-30 |date=3 May 2007}}</ref>
===Overconsumption===
{{See also|Planetary boundaries|Overconsumption}}


The ]<ref>{{cite news |last=Morales |first=Alex |date=24 October 2006 |title=Canada |publisher=Bloomberg |url=https://www.bloomberg.com/apps/news?pid=20601082&sid=asybYkLBp_tk |access-date=30 November 2011}}</ref><ref>{{cite web |title=WWF – Living Planet Report 2006 |url=http://www.panda.org/news_facts/publications/living_planet_report/lp_2006/index.cfm |access-date=30 November 2011 |publisher=Panda.org}}</ref> (WWF) and ] have argued that the annual ] of Earth has exceeded, as measured using the ]. In 2006, WWF's '']'' stated that in order for all humans to live with the current consumption patterns of Europeans, we would be spending three times more than what the planet can renew.<ref>{{cite web |title=WWF Living planet report |url=http://www.panda.org/news_facts/publications/living_planet_report/index.cfm |access-date=30 November 2011 |publisher=Panda.org}}</ref> According to these calculations, humanity as a whole was using by 2006 40% more than what Earth can regenerate.<ref>{{cite web |title=Data and Methodology |url=https://www.footprintnetwork.org/resources/data/ |access-date=6 March 2020 |website=footprintnetwork.org}}</ref> Another study by the WWF in 2014 found that it would take the equivalent of 1.5 Earths of bio-capacity to meet humanity's current levels of consumption.<ref>{{cite news |last=Carrington |first=Damian |date=30 September 2014 |title=Earth has lost half of its wildlife in the past 40 years, says WWF |work=] |url=https://www.theguardian.com/environment/2014/sep/29/earth-lost-50-wildlife-in-40-years-wwf |access-date=3 January 2017}}</ref> However, ] of ] states the view: "the poor want to get rich, and I want them to get rich," with a later addition, "of course we have to change consumption habits,... but we've also got to stabilize our numbers".<ref>{{cite news |last1=Martin |first1=Roger |year=2010 |title=Stopping at two children is better for the planet |url=http://news.bbc.co.uk/1/hi/programmes/hardtalk/9281866.stm |work=BBC HARDtalk}} Interviewed by Carrie Gracie</ref>
According to the ''Far Eastern Economic Review'', Asia alone will have at least 10 'hypercities' by 2025, that is, cities inhabited by more than 19 million people, including ] (24.9 million people), ] (25 million), ] (26.5 million), ] (27 million) and ] (33 million).<ref>{{cite web|url=http://www.atimes.com/atimes/Front_Page/HE20Aa01.html |title=Planet of Slums by Mike Davis |publisher=Atimes.com |date=20 May 2006 |accessdate=2011-11-30}}</ref> ] has grown from 300,000 in 1950 to an estimated 15 million today, and the Nigerian government estimates that city will have expanded to 25 million residents by 2015.<ref>{{cite web|url=http://www3.nationalgeographic.com/places/cities/city_lagos.html |title=Lagos, Nigeria facts |publisher=National Geographic |accessdate=2011-11-30}}</ref> Chinese experts forecast that Chinese cities will contain 800 million people by 2020.<ref>{{cite web|author=english@peopledaily.com.cn |url=http://english.people.com.cn/200409/16/eng20040916_157275.html |title=China's urban population to reach 800 to 900 million by 2020: expert |work=People's Daily |date=16 September 2004 |accessdate=2011-11-30}}</ref>


Critics have questioned the simplifications and statistical methods used in calculating ecological footprints. Therefore, ] and its partner organizations have engaged with national governments and international agencies to test the results—reviews have been produced by France, Germany, the European Commission, Switzerland, Luxembourg, Japan and the ].<ref>{{cite web |title=Publications – Global Footprint Network |url=http://www.footprintnetwork.org/en/index.php/GFN/page/publications/ |access-date=17 September 2017}}</ref> Some point out that a more refined method of assessing Ecological Footprint is to designate ] categories of consumption.<ref>{{cite journal |author=Jeroen C.J.M. van den Bergh |author2=Harmen Verbruggen |year=1999 |title=Spatial sustainability, trade and indicators: an evaluation of the 'ecological footprint' |url=http://www.tinbergen.nl/discussionpapers/98105.pdf |url-status=dead |journal=Ecological Economics |volume=29 |issue=1 |pages=61–72 |doi=10.1016/S0921-8009(99)00032-4 |bibcode=1999EcoEc..29...61V |archive-url=https://web.archive.org/web/20071009210421/http://www.tinbergen.nl/discussionpapers/98105.pdf |archive-date=9 October 2007}}</ref><ref>{{cite web |title=Planning and Markets: Peter Gordon and Harry W. Richardson |url=http://www-pam.usc.edu/volume1/v1i1a2print.html |url-status=dead |archive-url=https://web.archive.org/web/20100627044350/http://www-pam.usc.edu/volume1/v1i1a2print.html |archive-date=27 June 2010 |access-date=30 November 2011 |publisher=Pam.usc.edu}}</ref>
==Causes==
]]]
From a historical perspective, ]s have coincided with population explosions. There have been three major technological revolutions – the tool-making revolution, the ], and the ] – all of which allowed humans more access to food, resulting in subsequent population explosions.<ref>Deevey, E.S. (1960). "The Human Population", ''Scientific American'', Volume 203, pp.195–204.</ref><ref>Huesemann, M.H., and J.A. Huesemann (2011). , "Unintended Consequences of Technological Revolutions", New Society Publishers, Gabriola Island, Canada, {{ISBN|0865717044}}, pp. 43–46.</ref> For example, the use of tools, such as bow and arrow, allowed primitive hunters greater access to high energy foods (e.g. animal meat). Similarly, the transition to farming about 10,000 years ago greatly increased the overall food supply, which was used to support more people. Food production further increased with the ] as machinery, ]s, ]s, and ]s were used to increase land under cultivation as well as crop yields.<ref>Huesemann, M.H., and J.A. Huesemann (2011). , "Unintended Consequences of Industrial Agriculture", New Society Publishers, Gabriola Island, Canada, pp. 23–25.</ref> In short, similar to ] that multiply in response to increased food supply, humans have increased their population as soon as food became more abundant as a result of technological innovations.


===Carrying capacity===
Significant increases in human population occur whenever the ] exceeds the ] for extended periods of time. Traditionally, the fertility rate is strongly influenced by cultural and social norms that are rather stable and therefore slow to adapt to changes in the social, technological, or environmental conditions. For example, when death rates fell during the 19th and 20th century – as a result of improved sanitation, child immunizations, and other advances in medicine – allowing more newborns to survive, the fertility rate did not adjust downward fast enough, resulting in significant population growth. Prior to these changes, seven out of ten children died before reaching reproductive age, while today about 95% of newborns in industrialized nations reach adulthood.<ref>McKeown, T. (1988). ''The Origins of Human Disease'', Basil Blackwell, Oxford, UK.</ref>
{{Main|Sustainable population}}


Attempts have been made to estimate the world's ] for humans; the maximum population the world can host.<ref>Cohen, J.E. (1995). ''How many people can the earth support?'' W.W. Norton & Company, New York, NY, USA.</ref> A 2004 meta-analysis of 69 such studies from 1694 until 2001 found the average predicted maximum number of people the Earth would ever have was 7.7 billion people, with lower and upper meta-bounds at 0.65 and 98 billion people, respectively. They conclude: "recent predictions of stabilized world population levels for 2050 exceed several of our meta-estimates of a world population limit".<ref name="Van Den BerghRietveld2004">{{cite journal |last1=Van Den Bergh |first1=Jeroen C. J. M. |last2=Rietveld |first2=Piet |year=2004 |title=Reconsidering the Limits to World Population: Meta-analysis and Meta-prediction |journal=BioScience |volume=54 |issue=3 |page=195 |doi=10.1641/0006-3568(2004)0542.0.CO;2 |issn=0006-3568 |doi-access=free}}</ref>
===Agriculture and mining===
{{Expand section|date=February 2014}}


A 2012 United Nations report summarized 65 different estimated maximum ] sizes and the most common estimate was 8 billion.<ref> United Nations, June 2012</ref> Advocates of reduced population often put forward much lower numbers. ] stated in 2018 that the optimum population is between 1.5 and 2 billion.<ref>{{Cite news |last=Carrington |first=Damian |date=22 March 2018 |title=Paul Ehrlich: 'Collapse of civilisation is a near certainty within decades' |work=] |url=https://www.theguardian.com/cities/2018/mar/22/collapse-civilisation-near-certain-decades-population-bomb-paul-ehrlich |access-date=8 August 2020}}</ref> In 2022 Ehrlich and other contributors to the "Scientists' warning on population", including Eileen Crist, ], ] and Christopher Wolf, stated that environmental analysts put the sustainable level of human population at between 2 and 4 billion people.<ref name="Crist2022"/> Geographer Chris Tucker estimates that 3 billion is a sustainable number.<ref>{{Cite book |url=https://www.kirkusreviews.com/book-reviews/christopher-tucker/planet-of-3-billion/ |title=A PLANET OF 3 BILLION {{!}} Kirkus Reviews |language=en}}</ref>
] has been the main factor behind human population growth. This dates back to prehistoric times, when agricultural methods were first developed, and continues to the present day, with fertilizers, agrochemicals, large-scale mechanization, genetic manipulation, and other technologies.<ref>{{cite web|url=http://www.ck12.org/earth-science/Agriculture-and-Human-Population-Growth/|title=Agriculture and Human Population Growth|publisher=CK-12}}</ref>


==Proposed impacts==
Humans have always ] using the easiest, most accessible resources first. The richest farmland was plowed and the richest mineral ore mined first. Overpopulation will demand ever more creative means in which to satisfy these basic human needs.<ref>Ceballos, G.; Ehrlich, A. H.; Ehrlich, P. R. (2015). ''The Annihilation of Nature: Human Extinction of Birds and Mammals''. Baltimore, Maryland: Johns Hopkins University Press. pp. 146 {{ISBN|1421417189}}</ref>
===Poverty and infant and child mortality ===
{{Main|Demographic transition|Income and fertility}}


Although proponents of human overpopulation have expressed concern that growing population will lead to an increase in global ] and ], both indicators have declined over the last 200 years of population growth.<ref name="Our World in Data-2">{{cite web|title=Does population growth lead to hunger and famine?|url=https://ourworldindata.org/population-growth-and-famines|access-date=24 September 2018|website=Our World in Data}}</ref><ref name="Our World in Data">{{cite web|title=The short history of global living conditions and why it matters that we know it|url=https://ourworldindata.org/a-history-of-global-living-conditions-in-5-charts|access-date=24 September 2018|website=Our World in Data}}</ref>
===Psychological factors===
{{Unreferenced section|date=September 2016}}
Human ] and the cycle of entrenched ], as well as the rest of the world's reaction to it, are also causative factors. Areas with greater burden of disease and warfare, contrary to popular belief, do not experience less population growth over the long term, but far more over a sustained period as poverty becomes further entrenched{{Unreliable source?|date=September 2016}} . This is because parents and siblings who have experienced calamitous conditions suffer from a kind of ] about losing their family members and overcompensate by having "extra" babies. These extra babies and calamities fuel a ], and only in the small minority of cases does it cease{{Dubious|date=September 2016}}{{Unreliable source?|date=September 2016}} . As this cycle is compounded over generations, calamities such as disaster or war take on a ]. For example, the ] is said to have killed 30 million to date, yet during the last two decades money and initiatives to lower population growth by contraception have been sidelined in favor of combating ],<ref name="NYT">{{cite news|url=https://www.nytimes.com/2012/04/15/world/africa/in-nigeria-a-preview-of-an-overcrowded-planet.html?pagewanted=all |title=Nigeria Tested by Rapid Rise in Population |publisher=New York Times |date=2012-04-18 |accessdate=2012-11-26 |location=New York |first=Elisabeth |last=Rosenthal}}</ref> feeding the population explosion that we see in Africa today. In 1990, this continent's population was roughly 600 million; today it is over 1,050 million, 150 million more than if the HIV/AIDS crisis had never occurred.<ref>{{cite news| url=https://www.nytimes.com/2012/04/15/world/africa/in-nigeria-a-preview-of-an-overcrowded-planet.html?pagewanted=all | work=The New York Times | first=Elisabeth | last=Rosenthal | title=In Nigeria, a Preview of an Overcrowded Planet | date=14 April 2012}}</ref>


=== Environmental impacts ===
==Extremes==
{{Main|Human impact on the environment}}
Population growth rates between 1950 and 2012 range from a 0.5% increase in the case of Bulgaria to a more than 100 fold increase for the United Arab Emirates (from 79,050 to 8.5 million).<ref name="cenidb1950"/> Roughly half of all nations have quadrupled their populations since 1950.<ref name="cenidb1950">{{cite web|url=http://www.census.gov/population/international/data/idb/region.php?N=%20Results%20&T=6&A=both&RT=0&Y=1950&R=-1&C=AF,AL,AG,AQ,AN,AO,AV,AC,AR,AM,AA,AS,AU,AJ,BF,BA,BG,BB,BO,BE,BH,BN,BD,BT,BL,BK,BC,BR,BX,BU,UV,BM,BY,CB,CM,CA,CV,CJ,CT,CD,CI,CH,CO,CN,CF,CG,CW,CS,IV,HR,CU,UC,CY,EZ,DA,DJ,DO,DR,EC,EG,ES,EK,ER,EN,ET,FO,FJ,FI,FR,FP,GB,GA,GZ,GG,GM,GH,GI,GR,GL,GJ,GQ,GT,GK,GV,PU,GY,HA,HO,HK,HU,IC,IN,ID,IR,IZ,EI,IM,IS,IT,JM,JA,JE,JO,KZ,KE,KR,KN,KS,KV,KU,KG,LA,LG,LE,LT,LI,LY,LS,LH,LU,MC,MK,MA,MI,MY,MV,ML,MT,RM,MR,MP,MX,FM,MD,MN,MG,MJ,MH,MO,MZ,WA,NR,NP,NL,NC,NZ,NU,NG,NI,CQ,NO,MU,PK,PS,PM,PP,PA,PE,RP,PL,PO,RQ,QA,RO,RS,RW,TB,SH,SC,ST,RN,SB,VC,WS,SM,TP,SA,SG,RI,SE,SL,SN,NN,LO,SI,BP,SO,SF,OD,SP,CE,SU,NS,WZ,SW,SZ,SY,TW,TI,TZ,TH,TT,TO,TN,TD,TS,TU,TX,TK,TV,UG,UP,AE,UK,US,UY,UZ,NH,VE,VM,VI,VQ,WF,WE,WI,YM,ZA,ZI |title=International Programs – Region Summary – U.S. Census Bureau |publisher=Census.gov |date= |accessdate=2013-09-22}}</ref>
{{See also|Environmental impact of agriculture}}
A number of scientists have argued that ] and accompanying increase in ] threatens the world's ]s and the survival of human civilization.<ref>{{cite web | url=http://www.footprintnetwork.org/gfn_sub.php?content=overshoot | title=Ecological Debt Day | access-date=18 February 2013 | url-status=dead | archive-url=https://web.archive.org/web/20081217234021/http://www.footprintnetwork.org/gfn_sub.php?content=overshoot | archive-date=17 December 2008 }}
</ref><ref>{{cite web | url=http://www.nature.com/news/specials/planetaryboundaries/index.html#feature | title=Planetary Boundaries: Specials | work=Nature | date=23 September 2009 | access-date=18 February 2013 | archive-url=https://web.archive.org/web/20130212015050/http://www.nature.com/news/specials/planetaryboundaries/index.html#feature | archive-date=12 February 2013 | url-status=live }}</ref><ref>{{cite journal |last1=Bologna|first1=M. |last2=Aquino|first2=G. |date=2020 |title=Deforestation and world population sustainability: a quantitative analysis |url= |journal=] |volume= 10|issue=7631 |page=7631 |doi=10.1038/s41598-020-63657-6|pmid=32376879 |pmc=7203172|arxiv=2006.12202 |bibcode=2020NatSR..10.7631B|quote=Calculations show that, maintaining the actual rate of population growth and resource consumption, in particular forest consumption, we have a few decades left before an irreversible collapse of our civilisation.}}</ref><ref name="Bradshaw2021"/> The ], which was ratified by 58 member ] in 1994, states that "unprecedented" population growth aggravates many environmental problems, including rising levels of ], ], and pollution.<ref>{{cite web|url=http://www.interacademies.net/?id=3547 |title=IAP (login required) |publisher=InterAcademies.net |access-date=18 February 2013 |url-status=dead |archive-url=https://web.archive.org/web/20100210203604/http://www.interacademies.net/?id=3547 |archive-date=10 February 2010 }}</ref> Indeed, some analysts claim that overpopulation's most serious impact is its effect on the environment.<ref name=Timeenvir>{{cite news|url=http://www.time.com/time/specials/packages/article/0,28804,2097720_2097782_2097814,00.html|title=Overpopulation's Real Victim Will Be the Environment|magazine=Time|date=26 October 2011|access-date=18 February 2013|archive-url=https://web.archive.org/web/20130218180534/http://www.time.com/time/specials/packages/article/0,28804,2097720_2097782_2097814,00.html|archive-date=18 February 2013|url-status=dead}}</ref> Some scientists suggest that the overall ] during the ], particularly due to human population size and growth, ], overconsumption, ], and proliferation of technology, has pushed the planet into a new geological ] known as the ].<ref>{{Cite news|last=Subramanian|first=Meera|url=https://www.nature.com/articles/d41586-019-01641-5|title=Anthropocene now: influential panel votes to recognize Earth's new epoch|year=2019|work=] News|access-date=1 March 2020|quote="Twenty-nine members of the AWG supported the Anthropocene designation and voted in favour of starting the new epoch in the mid-twentieth century, when a rapidly rising human population accelerated the pace of industrial production, the use of agricultural chemicals and other human activities."}}</ref><ref>{{cite journal |last1=Syvitski|first1= Jaia |last2=Waters |first2=Colin N.|last3=Day|first3= John |display-authors=etal. |date=2020|title=Extraordinary human energy consumption and resultant geological impacts beginning around 1950 CE initiated the proposed Anthropocene Epoch|journal=Communications Earth & Environment|volume=1 |issue= 32|page= 32 |doi=10.1038/s43247-020-00029-y|bibcode= 2020ComEE...1...32S |s2cid= 222415797 |quote="Human population has exceeded historical natural limits, with 1) the development of new energy sources, 2) technological developments in aid of productivity, education and health, and 3) an unchallenged position on top of food webs. Humans remain Earth’s only species to employ technology so as to change the sources, uses, and distribution of energy forms, including the release of geologically trapped energy (i.e. coal, petroleum, uranium). In total, humans have altered nature at the planetary scale, given modern levels of human-contributed aerosols and gases, the global distribution of radionuclides, organic pollutants and mercury, and ecosystem disturbances of terrestrial and marine environments. Approximately 17,000 monitored populations of 4005 vertebrate species have suffered a 60% decline between 1970 and 2014, and ~1 million species face extinction, many within decades. Humans' extensive 'technosphere', now reaches ~30 Tt, including waste products from non-renewable resources."|doi-access=free|hdl=10810/51932|hdl-access=free}}</ref>


{{Pie chart
==Demographic transition==
| caption = '''] of ]s on Earth'''<ref>{{cite news |last= Carrington|first=Damian |date=21 May 2018 |title=Humans just 0.01% of all life but have destroyed 83% of wild mammals – study|url=https://www.theguardian.com/environment/2018/may/21/human-race-just-001-of-all-life-but-has-destroyed-over-80-of-wild-mammals-study|work=The Guardian |access-date=13 July 2019}}</ref><ref>{{cite journal |doi=10.1126/science.aau1397 |pmid=30213888 |title=Space for nature |journal=Science |volume=361 |issue=6407 |page=1051 |year=2018 |last1=Baillie |first1=Jonathan |last2=Zhang |first2=Ya-Ping |bibcode=2018Sci...361.1051B |doi-access=free }}</ref>
{{Main article|Demographic transition|Sub-replacement fertility}}
| label1 = ], mostly ] and ]s
The theory of demographic transition held that, after the ] and ] increase, ]s and ]s decline. However, as new data has become available, it has been observed that after a certain level of development (] equal to 0.86 or higher) the fertility increases again.<ref>{{Cite journal | last1 = Myrskylä | first1 = M. | last2 = Kohler | first2 = H. P. | last3 = Billari | first3 = F. C. | doi = 10.1038/nature08230 | title = Advances in development reverse fertility declines | journal = Nature | volume = 460 | issue = 7256 | pages = 741–743 | year = 2009 | pmid = 19661915| pmc = }}</ref> This means that both the worry that the theory generated about aging populations and the complacency it bred regarding the future environmental impact of population growth are misguided.
| value1 = 60 | color1 = blue
| label2 = ]s
| value2 = 36 | color2 = red
| label3 = ]
| value3 = 4 | color3 = green
}}


Some studies and commentary link population growth with ].{{refn|<ref name="Ripple-2019" /><ref>] (2004)."'' {{webarchive |url=https://web.archive.org/web/20160503035714/https://books.google.com/books?id=jE9mwoLXdwYC&pg=PA326&dq&hl=en |date=3 May 2016 }}''". ]. p.326. {{ISBN|0-521-52874-7}}</ref><ref>{{cite news|date=5 December 2009|title=Once taboo, population enters climate debate|url=https://www.independent.co.uk/climate-change/news/once-taboo-population-enters-climate-debate-5510946.html|access-date=3 August 2021|website=The Independent|language=en}}</ref><ref name="Agencies-2006">{{cite web|last=Agencies|date=6 January 2006|title=Population control 'vital' to curbing climate change|url=http://www.theguardian.com/environment/2006/jan/06/climatechange.climatechangeenvironment|access-date=24 August 2021|website=The Guardian|language=en}}</ref><ref name="WolfRipple2021">{{cite journal |last1=Wolf |first1=C. |last2=Ripple |first2=W.J. |last3=Crist |first3=E. |date=2021 |title=Human population, social justice, and climate policy |journal=Sustainability Science |volume=16 |issue=5 |pages=1753–1756 |url=https://scientistswarning.forestry.oregonstate.edu/sites/sw/files/Wolf2021.pdf |doi=10.1007/s11625-021-00951-w |bibcode=2021SuSc...16.1753W |s2cid=233404010 |access-date=26 October 2021 |archive-date=26 October 2021 |archive-url=https://web.archive.org/web/20211026131650/https://scientistswarning.forestry.oregonstate.edu/sites/sw/files/Wolf2021.pdf |url-status=dead }}</ref><ref>{{cite news |last=Laubichler|first=Manfred |date=3 November 2022 |title=8 billion humans: How population growth and climate change are connected as the 'Anthropocene engine' transforms the planet|url=https://theconversation.com/8-billion-humans-how-population-growth-and-climate-change-are-connected-as-the-anthropocene-engine-transforms-the-planet-193075|work=]|location= |access-date=6 November 2022}}</ref>}} Critics have stated that population growth alone may have less influence on climate change than other factors, such as ].<ref name="Stone-2017">{{cite web|last=Stone|first=Lyman|date=12 December 2017|title=Why you shouldn't obsess about "overpopulation"|url=https://www.vox.com/the-big-idea/2017/12/12/16766872/overpopulation-exaggerated-concern-climate-change-world-population|access-date=10 September 2021|website=Vox|language=en}}</ref><ref name="Webb" /> The global consumption of ] is projected to rise by as much as 76% by 2050 as the global population increases, with this projected to have further ] such as ] and increased ] emissions.<ref name="Best2014">{{cite book |last= Best|first=Steven|date=2014 |title=The Politics of Total Liberation: Revolution for the 21st Century|publisher=]|page=160 |isbn=978-1137471116|doi=10.1057/9781137440723|author-link=Steven Best|quote=By 2050 the human population will top 9 billion, and world meat consumption will likely double.}}</ref><ref>{{cite news |last= Devlin|first=Hannah |date=19 July 2018 |title=Rising global meat consumption 'will devastate environment'|url=https://www.theguardian.com/environment/2018/jul/19/rising-global-meat-consumption-will-devastate-environment|work=The Guardian |access-date=28 September 2019}}</ref><ref>{{cite journal |last1=Godfray|first1=H. Charles J.|last2=Aveyard|first2=Paul|display-authors=etal.|date=2018 |title=Meat consumption, health, and the environment|url= https://ora.ox.ac.uk/objects/uuid:cc174e1d-0e3e-43ce-9d3b-ad7e204d0845|journal=Science |volume=361 |issue=6399 |pages= |doi=10.1126/science.aam5324|pmid=30026199 |bibcode=2018Sci...361M5324G |s2cid=49895246 |doi-access=free}}</ref> A July 2017 study published in '']'' argued that the most significant way individuals could mitigate their own ] is to have fewer children, followed by living without a vehicle, forgoing air travel, and adopting a ].<ref>{{cite news|last=Perkins|first=Sid|date=11 July 2017|title=The best way to reduce your carbon footprint is one the government isn't telling you about|url=https://www.science.org/content/article/best-way-reduce-your-carbon-footprint-one-government-isn-t-telling-you-about|work=]|access-date=9 December 2017|archive-url=https://web.archive.org/web/20171201030527/http://www.sciencemag.org/news/2017/07/best-way-reduce-your-carbon-footprint-one-government-isn-t-telling-you-about|archive-date=1 December 2017|url-status=live}}</ref> However, even in countries that have both large population growth and major ecological problems, it is not necessarily true that curbing the population growth will make a major contribution towards resolving all environmental problems that can be solved simply with an ] policy approach.<ref name="UN World Population Report 2001">{{cite web|url=https://www.un.org/esa/population/publications/wpm/wpm2001.pdf|archive-url=https://web.archive.org/web/20030403112038/http://www.un.org/esa/population/publications/wpm/wpm2001.pdf|url-status=dead|archive-date=3 April 2003|title=UN World Population Report 2001|page=31|access-date=16 December 2008}}</ref>
Factors cited in the old theory included such social factors as later ages of marriage, the growing desire of many women in such settings to seek careers outside ] and domestic work, and the decreased need of children in industrialized settings. The latter factor stems from the fact that children ] in small-scale agricultural societies, and work less in industrial ones; it has been cited to explain the decline in birth rates in industrializing regions.


Continued ] and overconsumption, particularly by the wealthy, have been posited as key drivers of ] and ],<ref>{{Cite journal|last1=Pimm|first1=S. L.|last2=Jenkins|first2=C. N.|last3=Abell|first3=R.|last4=Brooks|first4=T. M.|last5=Gittleman|first5=J. L.|last6=Joppa|first6=L. N.|last7=Raven|first7=P. H.|last8=Roberts|first8=C. M.|last9=Sexton|first9=J. O.|date=30 May 2014|title=The biodiversity of species and their rates of extinction, distribution, and protection|url=https://www.science.org/doi/10.1126/science.1246752|journal=Science|language=en|volume=344|issue=6187|doi=10.1126/science.1246752|issn=0036-8075|pmid=24876501|s2cid=206552746|quote=The overarching driver of species extinction is human population growth and increasing per capita consumption.}}</ref><ref>{{cite journal | last1 = Ceballos | first1 = Gerardo| last2 = Ehrlich| first2 = Paul R.| last3 = Barnosky| first3= Anthony D. | author-link3=Anthony David Barnosky|last4 = García | first4 = Andrés| last5 = Pringle | first5 = Robert M.| last6 = Palmer| first6 =Todd M. | year = 2015 | title = Accelerated modern human–induced species losses: Entering the sixth mass extinction | journal = ] | volume = 1 | issue = 5 | page = e1400253 | doi = 10.1126/sciadv.1400253 | pmid= 26601195| pmc=4640606| bibcode = 2015SciA....1E0253C|quote=All of these are related to human population size and growth, which increases consumption (especially among the rich), and economic inequity.}}</ref><ref name="Bradshaw2021">{{cite journal |journal=Frontiers in Conservation Science|date=2021 |title=Underestimating the Challenges of Avoiding a Ghastly Future |volume=1 |issue= |pages= |doi=10.3389/fcosc.2020.615419 |last1=Bradshaw |first1=Corey J. A. |last2=Ehrlich |first2=Paul R. |last3=Beattie |first3=Andrew |last4=Ceballos |first4=Gerardo |last5=Crist |first5=Eileen |last6=Diamond |first6=Joan |last7=Dirzo |first7=Rodolfo |last8=Ehrlich |first8=Anne H. |last9=Harte |first9=John |last10=Harte |first10=Mary Ellen |last11=Pyke |first11=Graham |last12=Raven |first12=Peter H. |last13=Ripple |first13=William J. |last14=Saltré |first14=Frédérik |last15=Turnbull |first15=Christine |last16=Wackernagel |first16=Mathis |last17=Blumstein |first17=Daniel T. |s2cid=231589034 |doi-access=free|quote= Large populations and their continued growth are also drivers of soil degradation and biodiversity loss. More people means that more synthetic compounds and dangerous throw-away plastics are manufactured, many of which add to the growing toxification of the Earth.}}</ref><ref name="Dasgupta"/> with some researchers and environmentalists specifically suggesting this indicates a human overpopulation scenario.<ref name="Ceballos2017">{{cite journal| last1=Ceballos|first1=Gerardo|last2=Ehrlich|first2=Paul R |last3=Dirzo|first3=Rodolfo|date=23 May 2017|title=Biological annihilation via the ongoing sixth mass extinction signaled by vertebrate population losses and declines|journal=]|volume=114|issue=30|pages=E6089–E6096|doi=10.1073/pnas.1704949114|quote=Much less frequently mentioned are, however, the ultimate drivers of those immediate causes of biotic destruction, namely, human overpopulation and continued population growth, and overconsumption, especially by the rich. These drivers, all of which trace to the fiction that perpetual growth can occur on a finite planet, are themselves increasing rapidly.|pmc=5544311|pmid=28696295|bibcode=2017PNAS..114E6089C |doi-access=free}}</ref><ref name="978-0820343853 p83">{{cite book |editor1-last=Crist |editor1-first=Eileen |editor2-last=Cafaro |editor2-first=Philip |date=2012 |title=Life on the Brink: Environmentalists Confront Overpopulation |url=https://books.google.com/books?id=heOrAAAAQBAJ&pg=PA83 |location= |publisher=] |page=83 |isbn=978-0820343853}}</ref><ref name="Cafaro2022">{{Cite journal |last1=Cafaro |first1=Philip |last2=Hansson |first2=Pernilla |last3=Götmark |first3=Frank |date=August 2022 |title=Overpopulation is a major cause of biodiversity loss and smaller human populations are necessary to preserve what is left |journal=] |volume=272 |at=109646 |issn=0006-3207 |doi=10.1016/j.biocon.2022.109646|bibcode=2022BCons.27209646C |s2cid=250185617 |url=https://www.sustainable.soltechdesigns.com/Overpopulation-and-biodiversty-loss(2022).pdf}}</ref> The '']'', released by ] in 2019, states that human population growth is a factor in biodiversity loss.<ref>{{cite news|last=Watts|first=Jonathan|date=6 May 2019|title=Human society under urgent threat from loss of Earth's natural life|url=https://www.theguardian.com/environment/2019/may/06/human-society-under-urgent-threat-loss-earth-natural-life-un-report|work=]|access-date=23 June 2019|archive-url=https://web.archive.org/web/20190518041123/https://www.theguardian.com/environment/2019/may/06/human-society-under-urgent-threat-loss-earth-natural-life-un-report|archive-date=18 May 2019|url-status=live}}</ref><ref name="Stokstad2019">{{cite web|url=https://www.science.org/content/article/landmark-analysis-documents-alarming-global-decline-nature|title=Landmark analysis documents the alarming global decline of nature|last=Stokstad|first=Erik|date=5 May 2019|website=]|publisher=]|language=en|access-date=11 August 2020|quote="Driving these threats are the growing human population, which has doubled since 1970 to 7.6 billion, and consumption. (Per capita of use of materials is up 15% over the past 5 decades.)"}}</ref> IGI Global has uncovered the growth of the human population caused encroachment in wild habitats which have led to their destruction, "posing a potential threat to biodiversity components".<ref>{{cite book |last1=Uniyal |first1=Shivani |last2=Paliwal |first2=Rashmi |last3=Kaphaliya |first3=Bhumija |last4=R.K. |first4=Sharma |title=Environmental issues surrounding human overpopulation |date=2017 |publisher=Information Science Reference |isbn=978-1-5225-1684-2 |doi=10.4018/978-1-5225-1683-5.ch001 |url=https://www.researchgate.net/publication/312011571 |access-date=20 October 2022 |archive-url=https://web.archive.org/web/20220129134521/https://www.researchgate.net/publication/312011571_Human_Overpopulation |archive-date=29 January 2022 |language=en |format=PDF |chapter=1}}</ref>
Many countries have high population growth rates but lower ]s because high population growth in the past skewed the age demographic toward a young age, so the population still rises as the more numerous younger generation approaches maturity.<ref name=Ehrlich-Books/>


Some scientists and environmentalists, including ],<ref>{{cite web|url=http://people.morrisville.edu/~reymers/readings/ANTH101/WorstMistake-Diamond.pdf|title=The Worst Mistake of the Human Race|work=Jared Diamond, UCLA School of Medicine}}</ref> ], ]<ref name="Alberro" /> and ],<ref>{{cite web|date=15 January 2020|title=David Attenborough warns 'human beings have overrun the world' in new film|url=https://inews.co.uk/news/a-life-on-our-planet-trailer-david-attenborough-new-film-teaser-release-date-385845|access-date=7 September 2021|website=inews.co.uk|language=en}}</ref> contend that population growth is devastating to ]. Wilson for example, has expressed concern when '']'' reached a population of six billion their ] that had ever existed by over 100 times.<ref name="978-0820343853 p83"/> ], the executive director of the ], stated in December 2022 as the human population reached a milestone of 8 billion and as delegates were meeting for the ], that "we need to understand that the more people there are, the more we put the Earth under heavy pressure. As far as biodiversity is concerned, we are at war with nature."<ref>{{cite news |last=Greenfield|first=Patrick |date=6 December 2022|title='We are at war with nature': UN environment chief warns of biodiversity apocalypse|url=https://www.theguardian.com/environment/2022/dec/06/cop-15-un-chief-biodiversity-apocalypse|work=The Guardian|location= |access-date=5 January 2023}}</ref>
"Demographic entrapment" is a concept developed by Maurice King, Honorary Research Fellow at the ], who posits that this phenomenon occurs when a country has a population larger than its carrying capacity, no possibility of migration, and exports too little to be able to import food. This will cause starvation. He claims that for example many sub-Saharan nations are or will become stuck in demographic entrapment, instead of having a demographic transition.<ref>{{Cite journal | last1 = King | first1 = M. | last2 = Elliott | first2 = C. | doi = 10.1136/bmj.313.7063.995 | title = Averting a world food shortage: Tighten your belts for CAIRO II | journal = BMJ | volume = 313 | issue = 7063 | pages = 995–997 | year = 1996 | pmid = 8892423| pmc =2352328 }}</ref>


Human overpopulation and continued population growth are also considered by some, including animal rights attorney Doris Lin and philosopher ], to be an ] issue, as more human activity means the destruction of animal habitats and more direct killing of animals.<ref>{{cite web |url=https://www.thoughtco.com/effects-of-human-overpopulation-127867 |title=Human Overpopulation |last=Lin|first= Doris |date= 3 July 2019 |website=] |publisher= |access-date= 20 October 2021 |quote=Human overpopulation is an animal rights issue as well as an environmental issue and a human rights issue. Human activities, including mining, transportation, pollution, agriculture, development, and logging, take habitat away from wild animals as well as kill animals directly.}}</ref><ref name="Best2014" />{{rp|146}}
For the world as a whole, the number of ] decreased from 5.02 to 2.65 between 1950 and 2005. A breakdown by region is as follows:


===Resource depletion===
* Europe – 2.66 to 1.41
{{Main|Resource depletion|overconsumption}}
* North America – 3.47 to 1.99
* Oceania – 3.87 to 2.30
* Central America – 6.38 to 2.66
* South America – 5.75 to 2.49
* Asia (excluding Middle East) – 5.85 to 2.43
* Middle East & North Africa – 6.99 to 3.37
* Sub-Saharan Africa – 6.7 to 5.53


Some commentary has attributed ], such as ], ] and ], to overpopulation<ref>" {{webarchive |url=https://web.archive.org/web/20131225120645/http://www.scientificamerican.com/article.cfm?id=growing-population-poses-malthusian-dilemma |date=25 December 2013 }}". ] (2 October 2009).</ref> and suggested it could lead to a diminished quality of human life.<ref name="Nielsen">Ron Nielsen, ''The Little Green Handbook: Seven Trends Shaping the Future of Our Planet'', Picador, New York (2006) {{ISBN|978-0-312-42581-4}}</ref> Ecologist ] was one such proponent, saying "with the imbalance growing between population numbers and vital life sustaining resources, humans must actively conserve cropland, freshwater, energy, and biological resources. There is a need to develop renewable energy resources. Humans everywhere must understand that rapid population growth damages the Earth's resources and diminishes human well-being."<ref>David Pimentel, et al. {{webarchive |url=https://web.archive.org/web/20160710200107/http://dieoff.org/page174.htm |date=10 July 2016 }}, Dieoff.org</ref><ref>Lester R. Brown, Gary Gardner, Brian Halweil (September 1998). {{webarchive |url=https://web.archive.org/web/20160303181402/http://www.worldwatch.org/system/files/EWP143.pdf |date=3 March 2016 }}, ], {{ISBN|1-878071-45-9}}</ref>
Excluding the observed reversal in fertility decrease for high development, the projected world number of children born per woman for 2050 would be around 2.05. Only the Middle East & North Africa (2.09) and Sub-Saharan Africa (2.61) would then have numbers greater than 2.05.<ref>{{cite web|url=http://earthtrends.wri.org/searchable_db/results.php?years=1950-1955,1955-1960,1960-1965,1965-1970,1970-1975,1975-1980,1980-1985,1985-1990,1990-1995,1995-2000,2000-2005,2045-2050&variable_ID=369&theme=4&cID=&ccID=0,1,6,2,3,5,8,7,4 |title=World Resources Institute |publisher=Earthtrends.wri.org |accessdate=2011-11-30 |deadurl=yes |archiveurl=https://web.archive.org/web/20120117215622/http://earthtrends.wri.org/searchable_db/results.php?years=1950-1955%2C1955-1960%2C1960-1965%2C1965-1970%2C1970-1975%2C1975-1980%2C1980-1985%2C1985-1990%2C1990-1995%2C1995-2000%2C2000-2005%2C2045-2050&variable_ID=369&theme=4&cID=&ccID=0%2C1%2C6%2C2%2C3%2C5%2C8%2C7%2C4 |archivedate=17 January 2012 |df= }}</ref>


==Carrying capacity==
{{Main article|Carrying capacity}}
] placard in ]. It shows some negative effects of having too many children.]]

Some groups (for example, the ]<ref>{{cite news|last=Morales |first=Alex |url=https://www.bloomberg.com/apps/news?pid=20601082&sid=asybYkLBp_tk |title=Canada |publisher=Bloomberg |date=2006-10-24 |accessdate=2011-11-30}}</ref><ref>{{cite web|url=http://www.panda.org/news_facts/publications/living_planet_report/lp_2006/index.cfm |title=WWF – Living Planet Report 2006 |publisher=Panda.org |accessdate=2011-11-30}}</ref> and ]) have stated that the carrying capacity for the human population has been exceeded as measured using the ]. In 2006, ]'s "]" stated that in order for all humans to live with the current consumption patterns of Europeans, we would be spending three times more than what the planet can renew.<ref>{{cite web|url=http://www.panda.org/news_facts/publications/living_planet_report/index.cfm |title=WWF LIving planet report |publisher=Panda.org |accessdate=2011-11-30}}</ref> Humanity as a whole was using, by 2006, 40 percent more than what Earth can regenerate.<ref>Ecological Footprint Atlas 2009, Global Footprint Network, www.footprintnetwork.org/atlas</ref> However, ] of ] states the view: "the poor want to get rich, and I want them to get rich," with a later addition, "of course we have to change consumption habits,... but we've also got to stabilise our numbers".<ref>{{cite web|last1=Martin|first1=Roger|first2=interviewed by Carrie Gracie|title=Stopping at two children is better for the planet|url=http://news.bbc.co.uk/1/hi/programmes/hardtalk/9281866.stm|publisher=BBC HARDtalk|year=2010}}</ref> Another study by the World Wildlife Fund in 2014 found that it would take the equivalent of 1.5 Earths of biocapacity to meet humanity's current levels of consumption.<ref>{{cite news|last=Carrington|first=Damian |url=https://www.theguardian.com/environment/2014/sep/29/earth-lost-50-wildlife-in-40-years-wwf|title=Earth has lost half of its wildlife in the past 40 years, says WWF |publisher=]|date=30 September 2014 |accessdate=3 January 2017}}</ref>

But critics question the simplifications and statistical methods used in calculating Ecological Footprints. Therefore, Global Footprint Network and its partner organizations have engaged with national governments and international agencies to test the results – reviews have been produced by France, Germany, the European Commission, Switzerland, Luxembourg, Japan and the United Arab Emirates.<ref>http://www.footprintnetwork.org/en/index.php/GFN/page/publications/</ref> Some point out that a more refined method of assessing Ecological Footprint is to designate sustainable versus non-sustainable categories of consumption.<ref>{{cite journal|url=http://www.tinbergen.nl/discussionpapers/98105.pdf |title=Spatial sustainability, trade and indicators: an evaluation of the 'ecological footprint' |author=Jeroen C.J.M. van den Bergh and Harmen Verbruggen |journal=Ecological Economics |year=1999 |volume=29 | issue=1 | pages = 61–72|doi=10.1016/S0921-8009(99)00032-4}}</ref><ref>{{cite web|url=http://www-pam.usc.edu/volume1/v1i1a2print.html |title=Planning and Markets: Peter Gordon and Harry W. Richardson |publisher=Pam.usc.edu |accessdate=2011-11-30}}</ref> However, if yield estimates were adjusted for sustainable levels of production, the yield figures would be lower, and hence the ] estimated by the Ecological Footprint method even higher.

Other studies give particular attention to ] and increased world affluence.{{elucidate|date=March 2016}} <ref>{{Cite book
| last = Ryerson
| first = W. F.
| chapter = Population, The Multiplier of Everything Else
| editor-last = McKibben
| editor-first = D
| title = The Post Carbon Reader: Managing the 21st Century Sustainability Crisis
| volume =
| publisher = Watershed Media
| year = 2010
| isbn = 978-0-9709500-6-2
| postscript = <!-- Bot inserted parameter. Either remove it; or change its value to "." for the cite to end in a ".", as necessary. -->{{inconsistent citations}}
}}</ref><ref>{{cite book
| last =Brown
| first =L. R.
| title =World on the Edge
| publisher =Norton
| series =Earth Policy Institute
| year =2012
| pages =
| isbn =9781136540752
}}</ref>

In a 1994 study titled ''Food, Land, Population and the U.S. Economy'', ] and ] estimated the maximum ] for a ] at 200 million.<ref>{{Cite report
|author1=David Pimentel |author2=Mario Giampietro | date = 21 November 1994
| title = FOOD, LAND, POPULATION and the U.S. ECONOMY
| url = http://www.dieoff.com/page55.htm
| publisher = Carrying Capacity Network
| location = Washington, D.C.
| accessdate = 2014-09-07
}}</ref> And in order to achieve a sustainable economy and avert disaster, the United States would have to reduce its population by at least one-third, and ] would have to be reduced by two-thirds.<ref name=autogenerated2>{{cite web|url=http://dieoff.org/page40.htm |title=Eating Fossil Fuels &#124; EnergyBulletin.net |publisher=Dieoff.org |date=21 November 1994 |accessdate=2011-11-30}}</ref>

Many quantitative studies have estimated the world's carrying capacity for humans, that is, a limit to the world population.<ref>Cohen, J.E. (1995). ''How many people can the earth support?'' W.W. Norton & Company, New York, NY, USA.</ref> A meta-analysis of 69 such studies suggests a point estimate of the limit to be 7.7 billion people, while lower and upper meta-bounds for current technology are estimated as 0.65 and 98 billion people, respectively. They conclude: "recent predictions of stabilized world population levels for 2050 exceed several of our meta-estimates of a world population limit".<ref name="Van Den BerghRietveld2004">{{cite journal|last1=Van Den Bergh|first1=Jeroen C. J. M.|last2=Rietveld|first2=Piet|title=Reconsidering the Limits to World Population: Meta-analysis and Meta-prediction|journal=BioScience|volume=54|issue=3|year=2004|pages=195|issn=0006-3568|doi=10.1641/0006-3568(2004)0542.0.CO;2}}</ref>

==Effects of human overpopulation==
{{main article|Human impact on the environment}}

Humanity's overall impact on the planet is affected by many factors besides raw population. The lifestyle (including overall affluence and resource utilization) and the pollution (including ]) are equally important. In 2008, '']'' stated that the inhabitants of the developed nations of the world consume resources like oil and metals at a rate almost 32 times greater than those of the developing world, who make up the majority of the human population.<ref name="NYTimes_Diamond">Diamond, Jared: (2008-01-02). {{webarchive |url=https://web.archive.org/web/20161226011223/http://www.nytimes.com/2008/01/02/opinion/02diamond.html |date=26 December 2016 }} '']''</ref>

Some problems associated with or exacerbated by human overpopulation and over-consumption are:
* Inadequate fresh water<ref name = "Shiklomanov-11-32"/> for ] as well as ] and ] discharge. Some countries, like ], use energy-expensive ] to solve the problem of water shortages.<ref>{{cite web |url=http://www.ejpress.org/article/4873 |title=French-run water plant launched in Israel}}</ref><ref>{{cite web|url=http://www.edie.net/news/news_story.asp?id=11402&channel=0 |title=Black & Veatch-Designed Desalination Plant Wins Global Water Distinction |deadurl=yes |archiveurl=https://web.archive.org/web/20100324144203/http://www.edie.net/news/news_story.asp?id=11402&channel=0 |archivedate=24 March 2010 |df= }}</ref>
* Depletion of natural resources, especially ].<ref>Hubbert, M.K. ''Techniques of Prediction as Applied to Production of Oil and Gas'', US Department of Commerce, NBS Special Publication 631, May 1982</ref> ]
* Increased levels of air pollution, ], ] and ]. Once a country has industrialized and become wealthy, a combination of government regulation and technological innovation causes pollution to decline substantially, even as the population continues to grow.<ref name = "opinionjournal-Box">{{cite web|url=http://www.opinionjournal.com/columnists/pdupont/?id=110008416 |title=The Wall Street Journal Online – Outside the Box |publisher=Opinionjournal.com |accessdate=2011-11-30}}</ref>
* Deforestation and loss of ecosystems<ref name=wilson>Wilson, E.O. (2002). ''The Future of Life'', Vintage {{ISBN|0-679-76811-4}}</ref> that valuably contribute to the global atmospheric oxygen and carbon dioxide balance; about eight million hectares of forest are lost each year.<ref>{{cite web |url=http://www.mongabay.com/deforestation.htm |title=Worldwide Deforestation Rates}}</ref>
* Changes in atmospheric composition and consequent ].<ref>''International Energy Outlook 2000'', Energy Information Administration, Office of Integrated Analysis and Forecasting, ], Washington, D.C. (2000)</ref><ref>{{cite web|url=http://www.pwc.com/extweb/pwcpublications.nsf/docid/dfb54c8aad6742db852571f5006dd532 |title=The world in 2050:Impact of global growth on carbon emissions |publisher=Pwc.com |date=2006-10-30 |accessdate=2011-11-30}}</ref>
* Loss of ] and increase in ].<ref>UNEP, ''Global Environmental Outlook 2000'', Earthscan Publications, London, UK (1999)</ref> Deforestation and desertification can be reversed by adopting property rights, and this policy is successful even while the human population continues to grow.<ref>{{cite web|last=Polgreen |first=Lydia |url=http://www.iht.com/articles/2007/02/11/news/niger.php |title=Trees and crops reclaim desert in Niger |work=International Herald Tribune |date=11 February 2007 |accessdate=2011-11-30}}</ref>
* ] and contracting ]<ref>Leakey, Richard and Roger Lewin, 1996, ''The Sixth Extinction : Patterns of Life and the Future of Humankind'', Anchor, {{ISBN|0-385-46809-1}}</ref><ref>. ''].'' June 23, 2015. See also: {{cite journal | last1 = Ceballos | first1 = Gerardo| last2 = Ehrlich| first2 = Paul R.| last3 = Barnosky| first3= Anthony D. | last4 = García | first4 = Andrés| last5 = Pringle | first5 = Robert M.| last6 = Palmer| first6 =Todd M. | year = 2015 | title = Accelerated modern human–induced species losses: Entering the sixth mass extinction | journal = ] | volume = 1 | issue = 5 | page = e1400253 |url=http://advances.sciencemag.org/content/1/5/e1400253.full |doi = 10.1126/sciadv.1400253 | pmid= | pmc=}}</ref><ref>{{cite web|title=Human Population Growth and Extinction|publisher=Center for Biological Diversity|url=http://www.biologicaldiversity.org/campaigns/overpopulation/extinction/index.html}}</ref><ref>{{cite journal |last1=Pimm |first1=S. L. |last2=Jenkins |first2=C. N. |last3=Abell |first3=R. | last4=Brooks|first4=T. M. |last5= Gittleman|first5=J. L. |last6= Joppa |first6=L. N. |last7=Raven|first7=P. H. |last8=Roberts |first8=C. M.|last9= Sexton |first9=J. O.|date=30 May 2014 |title=The biodiversity of species and their rates of extinction, distribution, and protection |url=http://static.squarespace.com/static/51b078a6e4b0e8d244dd9620/t/538797c3e4b07a163543ea0f/1401395139381/Pimm+et+al.+2014.pdf|journal= ] |volume= 344|issue=6187|pages= |doi=10.1126/science.1246752 |access-date= 15 December 2016|quote=The overarching driver of species extinction is human population growth and increasing per capita consumption.}}</ref><ref>{{cite journal| last1=Ceballos|first1=Gerardo|last2=Ehrlich|first2=Paul R |last3=Dirzo|first3=Rodolfo|date=23 May 2017|title=Biological annihilation via the ongoing sixth mass extinction signaled by vertebrate population losses and declines|url=http://www.pnas.org/content/early/2017/07/05/1704949114.full|journal=]|DOI=10.1073/pnas.1704949114}}</ref> from reduced habitat in ]s due to ] techniques that sometimes are practiced by ], especially in countries with rapidly expanding rural populations; present ] rates may be as high as 140,000 ] lost per year.<ref name="Pimm">{{cite journal | last1 = Pimm | first1 = Stuart L. | last2 = Russell| first2 =Gareth J. | last3 = Gittleman| first3= John L. | last4 = Brooks| first4 =Thomas M. | year = 1995 | title = The Future of Biodiversity | journal = ] | volume = 269| issue = 5222 | pages =347–350 | doi = 10.1126/science.269.5222.347| pmid= | pmc=}}</ref> As of February 2011, the ] lists a total of 801 animal species having gone extinct during recorded human history,<ref>{{cite web|url=http://www.iucnredlist.org/documents/2008RL_stats_table_3a_v1223294385.pdf |title=IUCN Red List |accessdate=2009-09-30 |deadurl=bot: unknown |archiveurl=https://web.archive.org/web/20090306194130/http://www.iucnredlist.org/documents/2008RL_stats_table_3a_v1223294385.pdf |archivedate=6 March 2009 |df=dmy-all }}</ref> although the vast majority of extinctions are thought to be undocumented.<ref name="Pimm"/> Biodiversity would continue to grow at an exponential rate if not for human influence.<ref>{{cite journal |author=Sahney, S., Benton, M.J. and Ferry, P.A. |year=2010 |title=Links between global taxonomic diversity, ecological diversity and the expansion of vertebrates on land |journal=] |doi=10.1098/rsbl.2009.1024 |volume=6 |pages=544–547 |format=PDF |issue=4 |pmid=20106856 |pmc=2936204}}</ref> Sir ], former chief scientific adviser to the UK government, told a parliamentary inquiry: "It is self-evident that the massive growth in the ] through the 20th century has had more impact on biodiversity than any other single factor."<ref>" {{webarchive |url=https://web.archive.org/web/20160927193654/https://www.theguardian.com/society/2007/jul/11/comment.climatechange |date=27 September 2016 }}". The Guardian. July 11, 2007.</ref><ref>" {{webarchive |url=https://web.archive.org/web/20131110212314/http://www.scientificamerican.com/article.cfm?id=sixth-extinction |date=10 November 2013 }}". ''Scientific American''. August 12, 2008.</ref> ] said population growth is one of the main drivers of the Earth's extinction crisis.<ref>{{cite web |url=http://www.cnn.com/2016/12/12/world/sutter-vanishing-help/|title=How to stop the sixth mass extinction |first=John D. |last=Sutter |date=December 12, 2016|work=CNN|accessdate=December 19, 2016}}</ref><ref name=Ehrlich-Books/>
{{quote box|align=right|width=25em|quote=The ], ], ], ], ], ], ] and ] are all victims of human overpopulation.|source=—], 2009<ref>. ] for ]. March 8, 2009</ref>}}
* High infant and child mortality.<ref>U.S. National Research Council, Commission on the Science of Climate Change, Washington, D.C. (2001)</ref> High rates of infant mortality are associated with poverty. Rich countries with high population densities have low rates of infant mortality.<ref>]</ref>
*Intensive ] to support large populations. It results in human threats including the evolution and spread of ] diseases, excessive air and water pollution, and new viruses that infect humans.<ref name=Ehrlich-Books/>
* Increased chance of the emergence of new ]s and ]s.<ref>{{cite web|url=http://www.cdc.gov/ncidod/EID/vol11no12/05-0997.htm |title="Emerging Infectious Diseases" by Mark E.J. Woolhouse and Sonya Gowtage-Sequeria |publisher=Cdc.gov |accessdate=2011-11-30}}</ref> For many environmental and social reasons, including overcrowded living conditions, ] and inadequate, inaccessible, or non-existent health care, the poor are more likely to be exposed to ]s.<ref>{{cite web|url=http://www.who.int/infectious-disease-report/pages/ch2text.html |title=WHO Infectious Diseases Report |publisher=Who.int |accessdate=2011-11-30}}</ref>
* ], ]<ref name = "FAO-Italy"/> or poor diet with ill health and diet-deficiency diseases (e.g. ]). However, rich countries with high population densities do not have famine.<ref name=w1/>
* Poverty coupled with inflation in some regions and a resulting low level of capital formation. Poverty and inflation are aggravated by bad government and bad economic policies. Many countries with high population densities have eliminated absolute poverty and keep their inflation rates very low.<ref name="heritage-Index-Economic">{{cite web|last=Sherk |first=James |url=http://www.heritage.org/research/features/index/countries.cfm |title=Index of Economic Freedom |publisher=Heritage.org |accessdate=2011-11-30 |deadurl=yes |archiveurl=https://web.archive.org/web/20080213211732/http://www.heritage.org/research/features/index/countries.cfm |archivedate=13 February 2008 |df= }}</ref>
* Low ] in countries with fastest growing populations.<ref>{{Cite journal | last1 = McGranahan | first1 = G. | last2 = Lewin | first2 = S. | last3 = Fransen | first3 = T. | last4 = Hunt | first4 = C. | last5 = Kjellén | first5 = M. |title=News and notes: Environmental change and human health in countries of Africa, the Caribbean and the Pacific| last6 = Pretty | first6 = J. | last7 = Stephens | first7 = C. | last8 = Virgin | first8 = I. | journal = Global Change and Human Health | volume = 1 | pages = 9 | year = 2000 | doi = 10.1023/A:1011567429284 | pmid = | pmc = }}</ref>
* Unhygienic living conditions for many based upon water resource depletion, discharge of raw sewage<ref>{{cite web|url=http://www.dbc.uci.edu/~sustain/suscoasts/krismin.html |title=Wastewater Pollution in China |publisher=Dbc.uci.edu |accessdate=2011-11-30}}</ref> and solid waste disposal. However, this problem can be reduced with the adoption of sewers. For example, after ] installed sewers, its infant mortality rate fell substantially.<ref>{{cite web|title=Clean water could save millions of lives|url=http://the-spark.net/np787404.html|accessdate=9 July 2014}}</ref>
* Elevated crime rate due to drug cartels and increased theft by people stealing resources to survive.<ref>American Council for the United Nations University (2002)</ref>
* Conflict over scarce resources and crowding, leading to increased levels of warfare.<ref>Heidelberger Institut fur International Konfliktforschung, ''Konfliktbarometer 2003: 12. Jarlickhe Konfliktanalyse'' University of Heidelberg, Germany (2004)</ref>
* Less personal freedom and more restrictive laws. Laws regulate interactions between humans. Law "serves as a primary social mediator of relations between people".{{citation needed|date=October 2012}}<!--where is the quote from? --> The higher the population density, the more frequent such interactions become, and thus there develops a need for more laws and/or more restrictive laws to regulate these interactions. It was even speculated by ] in 1958 that democracy is threatened due to overpopulation, and could give rise to ] style governments.<ref>{{cite web|title=BRAVE NEW WORLD REVISITED: overpopulation|url=http://www.huxley.net/bnw-revisited/index.html#overpop|accessdate=9 July 2014}}</ref>
* ] described the level of human population on the planet as a multiplier of all other environmental problems.<ref>{{cite web|title=People and Planet speech|url=https://www.youtube.com/watch?t=536&v=fK0rXRmC4DQ|publisher=]|ref=at 13mins,30secs into speech}}</ref> In 2013, he described humanity as "a plague on the Earth" that needs to be controlled by limiting population growth.<ref> {{webarchive |url=https://web.archive.org/web/20161120085247/http://www.telegraph.co.uk/news/earth/earthnews/9815862/Humans-are-plague-on-Earth-Attenborough.html |date=20 November 2016 }}. ''The Telegraph.'' 22 January 2013.</ref>

{{quote box|align=right|width=25em|quote=Rich western countries are now siphoning up the planet’s resources and destroying its ecosystems at an unprecedented rate. We want to build highways across the Serengeti to get more rare earth minerals for our cellphones. We grab all the fish from the sea, wreck the coral reefs and put carbon dioxide into the atmosphere. We have triggered a major extinction event ... A world population of around a billion would have an overall pro-life effect. This could be supported for many millennia and sustain many more human lives in the long term compared with our current uncontrolled growth and prospect of sudden collapse ... If everyone consumed resources at the US level – which is what the world aspires to – you will need another four or five Earths. We are wrecking our planet’s ]. |source=—], 2017<ref>McKie, Robin. (February 2017), '']''</ref>}}

Many of these problems are explored in the dystopic science fiction film '']'', where an overpopulated Earth suffers from food shortages, depleted resources and poverty and in the documentary "]".

Some economists, such as ]<ref>Sowell, Thomas (1998-02-12). . jewishworldreview.com</ref> and ]<ref name=w1>Williams, Walter (1999-02-24). {{webarchive |url=https://web.archive.org/web/20160515032842/http://www.jewishworldreview.com/cols/williams022499.asp |date=15 May 2016 }}. jewishworldreview.com</ref> argue that third world poverty and ] are caused in part by bad government and bad economic policies. Most biologists and sociologists see overpopulation as a serious threat to the quality of human life.<ref name=wilson/><ref name="Nielsen"/> Some ], such as the radical thinker and polemicist ], see human overpopulation as a threat to the entire ].<ref>Pentti Linkola, "Can Life Prevail?", Arktos Media, 2nd Revised ed. 2011. pp. 120–121. {{ISBN|1907166637}}.</ref>

==Resources==
Overpopulation does not depend only on the size or density of the population, but on the ratio of population to available sustainable resources. It also depends on how resources are managed and distributed throughout the population.

The resources to be considered when evaluating whether an ecological niche is overpopulated include ], clean air, food, shelter, warmth, and other resources necessary to sustain life. If the quality of human life is addressed, there may be additional resources considered, such as medical care, education, proper ], ] and energy supplies. Overpopulation places competitive stress on the basic life sustaining resources,<ref>" {{webarchive |url=https://web.archive.org/web/20131225120645/http://www.scientificamerican.com/article.cfm?id=growing-population-poses-malthusian-dilemma |date=25 December 2013 }}". ] (2009-10-02).</ref> leading to a diminished quality of life.<ref name="Nielsen">Ron Nielsen, ''The Little Green Handbook: Seven Trends Shaping the Future of Our Planet'', Picador, New York (2006) {{ISBN|978-0-312-42581-4}}</ref>

Directly related to maintaining the health of the human population is water supply, and it is one of the resources that experience the biggest strain. With the global population at about 7.5 billion, and each human theoretically needing 2 liters of drinking water, there is a demand for 15 billion liters of water each day to meet the minimum requirement for healthy living (United). Weather patterns, elevation, and climate all contribute to uneven distribution of fresh drinking water. Without clean water, good health is not a viable option. Besides drinking, water is used to create sanitary living conditions and is the basis of creating a healthy environment fit to hold human life. In addition to drinking water, water is also used for bathing, washing clothes and dishes, flushing toilets, a variety of cleaning methods, recreation, watering lawns, and farm irrigation.
Irrigation poses one of the largest problems, because without sufficient water to irrigate crops, the crops die and then there is the problem of food rations and starvation. In addition to water needed for crops and food, there is limited land area dedicated to food production, and not much more that is suitable to be added. Arable land, needed to sustain the growing population, is also a factor because land being under or over cultivated easily upsets the delicate balance of nutrition supply. There are also problems with location of arable land with regard to proximity to countries and relative population (Bashford 240). Access to nutrition is an important limiting factor in population sustainability and growth. No increase in arable land added to the still increasing human population will eventually pose a serious conflict. Only 38% of the land area of the globe is dedicated to agriculture, and there is not room for much more. Although plants produce 54 billion metric tons of carbohydrates per year, when the population is expected to grow to 9 billion by 2050, the plants may not be able to keep up (Biello). Food supply is a primary example of how a resource reacts when its carrying capacity is exceeded. By trying to grow more and more crops off of the same amount of land, the soil becomes exhausted. Because the soil is exhausted, it is then unable to produce the same amount of food as before, and is overall less productive. Therefore, by using resources beyond a sustainable level, the resource become nullified and ineffective, which further increases the disparity between the demand for a resource and the availability of a resource. There must be a shift to provide adequate recovery time to each one of the supplies in demand to support contemporary human lifestyles.
<ref>Bashford, Alison. "Population, Geopolitics, and International Organizations in the Mid Twentieth Century." Journal of World History 19.3 (2008): 327–347. Humanities Source Database. Web. 9 Nov 2013.</ref><ref>{{cite web|url=http://blogs.scientificamerican.com/observations/2012/09/26/will-humanity-face-a-carbohydrate-shortage/?WT_mc_id=SA_DD_20120927|title=Will Humanity Face a Carbohydrate Shortage?|publisher=Scientific American|date=2012-09-26|accessdate=2014-04-29|author=David Biello}}</ref><ref>{{cite web|url=http://www.census.gov/popclock|title=U.S. and World Population Clock|publisher=United States Census Bureau|accessdate=2014-04-29}}</ref>
]'s downtown, ]]]
] has stated that "With the imbalance growing between population numbers and vital life sustaining resources, humans must actively conserve cropland, freshwater, energy, and biological resources. There is a need to develop renewable energy resources. Humans everywhere must understand that rapid population growth damages the Earth's resources and diminishes human well-being."<ref>David Pimentel, et al. {{webarchive |url=https://web.archive.org/web/20160710200107/http://dieoff.org/page174.htm |date=10 July 2016 }}, Dieoff.org</ref><ref>Lester R. Brown, Gary Gardner, Brian Halweil (September 1998). {{webarchive |url=https://web.archive.org/web/20160303181402/http://www.worldwatch.org/system/files/EWP143.pdf |date=3 March 2016 }}, ], {{ISBN|1-878071-45-9}}</ref>

These reflect the comments also of the ] in their paper . "As the global population continues to grow...people will place greater and greater demands on the resources of our planet, including mineral and ], open space, ], and plant and animal resources." "Earth's natural wealth: an audit" by '']'' magazine states that many of the minerals that we use for a variety of products are in danger of running out in the near future.<ref name="usgs.gov">{{cite web|url=http://www.usgs.gov/newsroom/article.asp?ID%3D653#.U8X8t_S1zkw |title=Archived copy |accessdate=2014-07-16 |deadurl=no |archiveurl=https://web.archive.org/web/20160304093234/http://www.usgs.gov/newsroom/article.asp?ID=653 |archivedate=4 March 2016 |df=dmy }}</ref> A handful of geologists around the world have calculated the costs of new technologies in terms of the materials they use and the implications of their spreading to the developing world. All agree that the planet's booming population and rising standards of living are set to put unprecedented demands on the materials that only Earth itself can provide.<ref name="usgs.gov"/> Limitations on how much of these materials is available could even mean that some technologies are not worth pursuing long term.... "Virgin stocks of several metals appear inadequate to sustain the modern 'developed world' quality of life for all of Earth's people under contemporary technology".<ref>{{cite web|url=http://environment.newscientist.com/channel/earth/mg19426051.200-earths-natural-wealth-an-audit.html |title=Earth's natural wealth: an audit |publisher=Environment.newscientist.com |date=23 May 2007 |accessdate=2011-11-30}}</ref>

On the other hand, some ] researchers, such as ] and ] believe that resources exist for further population growth. In a 2010 study, they concluded that "there are not (and will never be) too many people for the planet to feed" according to ].<ref>{{cite news|url=http://www.independent.co.uk/opinion/commentators/dominic-lawson/dominic-lawson-the-population-timebomb-is-a-myth-2186968.html |title=Dominic Lawson: The population timebomb is a myth The doom-sayers are becoming more fashionable just as experts are coming to the view it has all been one giant false alarm |work=The Independent |location=UK |date=18 January 2011 |accessdate=2011-11-30}}</ref> Some critics warn, this will be at a high cost to the Earth: "the technological optimists are probably correct in claiming that overall world food production can be increased substantially over the next few decades... the environmental cost of what Paul R. and Anne H. Ehrlich describe as 'turning the Earth into a giant human feedlot' could be severe. A large expansion of agriculture to provide growing populations with improved diets is likely to lead to further ], loss of ], ], and pollution from pesticides and fertilizer runoff as farming intensifies and new land is brought into production."<ref>{{cite web|author=Post a Comment |url=http://www.sciam.com/article.cfm?articleID=000F3D47-C6D2-1CEB-93F6809EC5880000&pageNumber=1&catID=2 |title=Misleading Math about the Earth: Scientific American |publisher=Sciam.com |accessdate=2011-11-30}}</ref> Since we are intimately dependent upon the living systems of the Earth,<ref>{{cite web|url=http://nasadaacs.eos.nasa.gov/articles/2005/2005_mea.html |title=NASA Earth Science Data and Services: Checking Earth's Vital Signs |publisher=Nasadaacs.eos.nasa.gov |accessdate=2011-11-30}}</ref><ref>{{cite web|url=http://www.greenfacts.org/en/ecosystems/ |title=Ecosystem Change: Scientific Facts on Ecosystem Change |publisher=Greenfacts.org |date=2011-10-17 |accessdate=2011-11-30}}</ref><ref>{{cite web|url=http://pubs.usgs.gov/of/2002/of02-349/ |title=USGS OFR 02-349: Human Impact on the Planet: An Earth Science Perspective and Ethical Considerations |publisher=Pubs.usgs.gov |date=2002-10-07 |accessdate=2011-11-30}}</ref> some scientists have questioned the wisdom of further expansion.

According to the ], a four-year research effort by 1,360 of the world's prominent scientists commissioned to measure the actual value of natural resources to humans and the world, "The structure of the world's ecosystems changed more rapidly in the second half of the twentieth century than at any time in recorded human history, and virtually all of Earth's ecosystems have now been significantly transformed through human actions."<ref>{{cite web|url=http://www.greenfacts.org/en/ecosystems/millennium-assessment-3/1-ecosystem-change.htm#1p1 |title=1. How have ecosystems changed? |publisher=Greenfacts.org |date=2011-10-17 |accessdate=2011-11-30}}</ref> "Ecosystem services, particularly food production, timber and fisheries, are important for employment and economic activity. Intensive use of ecosystems often produces the greatest short-term advantage, but excessive and unsustainable use can lead to losses in the long term. A country could cut its forests and deplete its fisheries, and this would show only as a positive gain to GDP, despite the loss of capital assets. If the full economic value of ecosystems were taken into account in decision-making, their degradation could be significantly slowed down or even reversed."<ref name = "ecosystems-#3">{{cite web|url=http://www.greenfacts.org/en/ecosystems/#3 |title=Ecosystem Change: Scientific Facts on Ecosystem Change |publisher=Greenfacts.org |date=2011-10-17 |accessdate=2011-11-30}}</ref><ref>{{cite web|url=http://www.greenfacts.org/en/ecosystems/millennium-assessment-3/3-human-wellbeing-poverty.htm#2p0 |title=3. How have ecosystem changes affected human well-being and poverty alleviation? |publisher=Greenfacts.org |date=2011-10-17 |accessdate=2011-11-30}}</ref>

Another study by the ] (UNEP) called the ]<ref>{{cite web|url=http://www.unep.org/geo/geo4/media/ |title=Global Environmental Outlook – 4 |publisher=Unep.org |accessdate=2011-11-30}}</ref> which involved 1,400 scientists and took five years to prepare comes to similar conclusions. It "found that human consumption had far outstripped available resources. Each person on Earth now requires a third more land to supply his or her needs than the planet can supply."{{Page needed|date=November 2010}} It faults a failure to "respond to or recognize the magnitude of the challenges facing the people and the environment of the planet... 'The systematic destruction of the Earth's natural and nature-based resources has reached a point where the economic viability of economies is being challenged – and where the bill we hand to our children may prove impossible to pay'... The report's authors say its objective is 'not to present a dark and gloomy scenario, but an urgent call to action'. It warns that tackling the problems may affect the vested interests of powerful groups, and that the environment must be moved to the core of decision-making... '<ref>{{cite web|url=http://www.unep.org/geo/geo4/media/ |title=Global Environment Outlook: environment for development (GEO-4) |publisher=Unep.org |accessdate=2011-11-30}}</ref>{{Page needed|date=November 2010}}

Although all resources, whether mineral or other, are limited on the planet, there is a degree of self-correction whenever a scarcity or high-demand for a particular kind is experienced. For example, in 1990 known reserves of many natural resources were higher, and their prices lower, than in 1970, despite higher demand and higher consumption. Whenever a price spike would occur, the market tended to correct itself whether by substituting an equivalent resource or switching to a new technology.<ref>{{cite web|url=https://www.un.org/esa/population/publications/wpm/wpm2001.pdf|format=PDF|title=UN World Population Report 2001|page=34|accessdate=16 December 2008}}</ref>

===Fresh water===
{{Further information|Water crisis}}
] supplies, on which agriculture depends, are running low worldwide.<ref>Brown, Lester R. and Halweil, Brian (1999-09-23). . Worldwatch Institute.</ref><ref>{{cite book|author=Fred Pearce|title=When the Rivers Run Dry: Water—The Defining Crisis of the Twenty-first Century|url=https://books.google.com/books?id=C0_q-90H1aAC|year=2007|publisher=Beacon Press|isbn=978-0-8070-8573-8}}</ref> This ] is only expected to worsen as the population increases.<ref>{{cite book |url=https://books.google.com/books?id=1HEwh8nsljQC&printsec=frontcover&dq=Outgrowing+The+Earth:+The+Food+Security+Challenge+in+an+Age+of+Falling+Water+Tables+and+Rising+Temperature&hl=en&sa=X&ei=cUX9UtGFGJDksATpiYG4Dw&ved=0CCsQ6AEwAA#v=onepage&q=Outgrowing%20The%20Earth%3A%20The%20Food%20Security%20Challenge%20in%20an%20Age%20of%20Falling%20Water%20Tables%20and%20Rising%20Temperature&f=false |last=Worldwatch |first=The |title=Outgrowing the Earth: The Food Security Challenge in an Age of Falling Water Tables and Rising Temperatures: Books: Lester R. Brown |publisher=Amazon.com |isbn=0393060705}}</ref>

Potential problems with dependence on desalination are reviewed below, however, the majority of the world's freshwater supply is contained in the polar icecaps, and underground river systems accessible through springs and wells.

Fresh water can be obtained from salt water by ]. For example, ] derives two thirds of its freshwater by desalination. A number of ]ed desalination plants exist;<ref>{{cite web|title=Nuclear Desalination |url=http://www.uic.com.au/nip74.htm |website=https://web.archive.org/ |deadurl=yes |archiveurl=https://web.archive.org/web/20070208191547/http://www.uic.com.au/nip74.htm |archivedate=8 February 2007 }}</ref><ref name="stanford-cohen">{{cite journal|doi=10.1119/1.13440 |url=http://www.sustainablenuclear.org/PADs/pad11983cohen.pdf |title=Breeder reactors: A renewable energy source |author=Cohen, Bernard L. |journal=American Journal of Physics |volume=51 |issue=1 |pages=75–76 |year=1983 |bibcode=1983AmJPh..51...75C |deadurl=yes |archiveurl=https://web.archive.org/web/20130114062518/http://sustainablenuclear.org/PADs/pad11983cohen.pdf |archivedate=14 January 2013 |df=dmy-all }}</ref> however, the high costs of desalination, especially for poor countries, make impractical the transport of large amounts of desalinated seawater to interiors of large countries.<ref>{{cite web|url=http://www.thenation.com/doc/20020902/barlow |title=Who Owns Water? |publisher=Thenation.com |accessdate=2011-11-30}}</ref> The cost of desalination varies; ] is now desalinating water for a cost of 53 cents per cubic meter,<ref name = "ejpress-water"/> ] at 49 cents per cubic meter.<ref name = "edie-distinct"/> In the United States, the cost is 81 cents per cubic meter ($3.06 for 1,000 gallons).<ref>{{cite web|title=Desalination gets a serious look|url=http://www.lasvegassun.com/news/2008/mar/21/desalination-gets-serious-look/|website=http://www.lasvegassun.com}}</ref>

According to a 2004 study by Zhou and Tol, "one needs to lift the water by 2000 m, or transport it over more than 1600&nbsp;km to get transport costs equal to the desalination costs. Desalinated water is expensive in places that are both somewhat far from the sea and somewhat high, such as ] and ]. In other places, the dominant cost is desalination, not transport. This leads to somewhat lower costs in places like Beijing, ], ], ], and, of course, coastal cities like ]." Thus while the study is generally positive about the technology for affluent areas that are proximate to oceans, it concludes that "Desalinated water may be a solution for some water-stress regions, but not for places that are poor, deep in the interior of a continent, or at high elevation. Unfortunately, that includes some of the places with biggest water problems."<ref name="uni-hamburg.de">{{cite journal|journal=Water Resources Research|volume=41|pages=W03003|year=2005|doi=10.1029/2004WR003749|title=Evaluating the costs of desalination and water transport|author1=Zhou, Yuan |author2=Tol, Richard S. J.|bibcode=2005WRR....4103003Z|issue=3}}</ref> Another potential problem with desalination is the byproduction of saline ], which can be a major cause of marine pollution when dumped back into the oceans at high temperatures."<ref name="uni-hamburg.de"/>

The world's largest desalination plant is the ] Desalination Plant (Phase 2) in the ], which can produce 300 million cubic metres of water per year,<ref>{{cite web|url=http://www.worldwater.org/data20062007/Table21.pdf |title=100 Largest Desalination Plants Planned, in Construction, or in Operation—1 January 2005 |format=PDF |accessdate=2011-11-30}}</ref> or about 2500 gallons per second. The largest desalination plant in the US is the one at ], Florida, which began desalinating 25 million gallons (95000 m³) of water per day in December 2007. A 17 January 2008, article in the '']'' states, "Worldwide, 13,080 desalination plants produce more than 12 billion gallons of water a day, according to the International Desalination Association."<ref>{{cite web|title=Water, Water, Everywhere|url=https://www.wsj.com/news/articles/SB120053698876396483?mg=reno64-wsj&url=http%3A%2F%2Fonline.wsj.com%2Farticle%2FSB120053698876396483.html%3F|website=http://online.wsj.com}}</ref> After being desalinated at ], Saudi Arabia, water is pumped {{convert|200|mi|km}} inland though a pipeline to the capital city of ].<ref>{{cite web|title=Desalination is the Solution to Water Shortages |url=http://www.redorbit.com/news/science/1367352/desalination_is_the_solution_to_water_shortages|website=http://www.redorbit.com/}}</ref>

However, new data originating from the ] experiments and isotopic testing done by the ] show that the ]—which is under the largest, driest part of the earth's surface, has enough water in it to provide for "at least several centuries". In addition to this, new and highly detailed maps of the earth's underground reservoirs will be soon created from these technologies that will further allow proper budgeting of cheap water.<ref>Wald, Chelsea (2012-02-15). {{webarchive |url=https://web.archive.org/web/20150423103654/http://www.newscientist.com/article/mg21328512.200-uncharted-waters-probing-aquifers-to-head-off-war.html |date=23 April 2015 }}. New Scientist</ref>

===Food===
Some scientists argue that there is enough food to support the world population,<ref>{{cite journal|author1=Haynes, Michael |author2=Husan, Rumy |year= 2000 |title=National inequality and the catch-up period: Some "growth alone" scenarios" |journal=Journal of Economic Issues|volume=34|issue=3 |quote=In a world that now produces more food than is necessary to feed all its population , there is no excuse for hunger and starvation.|jstor=4227593|pages=693–705}}</ref><ref>{{Cite journal | last1 = Gilland | first1 = B. | doi = 10.1016/S0306-9192(02)00002-7 | title = World population and food supply | journal = Food Policy | volume = 27 | pages = 47–38 | year = 2002 | pmid = | pmc = }}</ref> and some dispute this, particularly if sustainability is taken into account.<ref>{{cite web|url=http://www.globalchange.umich.edu/globalchange2/current/lectures/food_supply/food.htm |title=Human Appropriation of the World's Food Supply |publisher=Globalchange.umich.edu |date=2000-12-15 |accessdate=2011-11-30 |deadurl=yes |archiveurl=https://web.archive.org/web/20111204153025/http://www.globalchange.umich.edu/globalchange2/current/lectures/food_supply/food.htm |archivedate=4 December 2011 |df= }}</ref>

Many countries rely heavily on imports. ] and ] rely on imports for 40% of their grain supply. ] and ] import more than 90%. And just 6 countries – ], Australia, Canada, France, ] and the USA – supply 90% of grain exports. In recent decades the US alone supplied almost half of world grain exports.<ref>{{cite web|url=http://www.earth-policy.org/Books/Out/Ote1_5.htm |title=Pushing Beyond the Earth's Limits The Japan Syndrome |publisher=Earth-policy.org |accessdate=2011-11-30}}</ref><ref name="The Food Bubble Economy">{{cite web|url=http://www.i-sis.org.uk/TFBE.php |title=The Food Bubble Economy |publisher=I-sis.org.uk |date=12 April 2002 |accessdate=2011-11-30}}</ref>

A 2001 United Nations report says population growth is "the main force driving increases in agricultural demand" but "most recent expert assessments are cautiously optimistic about the ability of global food production to keep up with demand for the foreseeable future (that is to say, until approximately 2030 or 2050)", assuming declining population growth rates.<ref>{{cite web|url=https://www.un.org/esa/population/publications/wpm/wpm2001.pdf|format=PDF|title=UN World Population Report 2001|page=38|accessdate=2008-12-16}}</ref>

However, the observed figures for 2007 show an actual increase in absolute numbers of undernourished people in the world, 923 million in 2007 versus 832 million in 1995.;<ref>] Economic and Social Development Department. {{webarchive |url=https://web.archive.org/web/20161026084651/http://www.fao.org/docrep/011/i0291e/i0291e00.htm |date=26 October 2016 }}. ] of the United Nations, 2008, p. 2.</ref> the more recent FAO estimates point to an even more dramatic increase, to 1.02 billion in 2009.<ref>{{cite web|title=1.02 billion people hungry|url=http://www.fao.org/news/story/en/item/20568/icode/|website=http://www.fao.org/}}</ref>

====Global perspective====
{{Further information|2007–2008 world food price crisis}}
] ]
The amounts of natural resources in this context are not necessarily fixed, and their distribution is not necessarily a ]. For example, due to the ] and the fact that more and more land is appropriated each year from wild lands for agricultural purposes, the worldwide production of food had steadily increased up until 1995. World food production per person was considerably higher in 2005 than 1961.


Although ] have been warned as a consequence of overpopulation, according to the ], global food production exceeds increasing demand from global population growth.<ref name="Nature 12-1-2015" /><ref name="Nature-2010">{{Cite journal|date=1 July 2010|title=Food: The growing problem|journal=Nature|language=en|volume=466|issue=7306|pages=546–547|doi=10.1038/466546a|pmid=20671687|s2cid=205057552|issn=1476-4687|doi-access=free}}</ref> Food insecurity in some regions is attributable to the globally unequal distribution of food supplies.<ref name="Nature 12-1-2015" />
As world population doubled from 3 billion to 6 billion, daily ] consumption in poor countries increased from 1,932 to 2,650, and the percentage of people in those countries who were malnourished fell from 45% to 18%. This suggests that Third World poverty and famine are caused by underdevelopment, not overpopulation.<ref>{{cite news| url=http://www.economist.com/science/displayStory.cfm?Story_ID=718860 | work=The Economist | title=The truth about the environment | date=2001-08-02}}</ref> However, others question these statistics.<ref name=autogenerated1>{{cite journal|url=http://www.nicholas.duke.edu/people/faculty/pimm/publications/pimmreprints/170_Pimm_Harvey_Nature.pdf |doi=10.1038/35102629|title=No need to worry about the future|year=2001|last1=Pimm|first1=Stuart|last2=Harvey|first2=Jeff|journal=Nature|volume=414|issue=6860|page=149}}</ref> From 1950 to 1984, as the ] transformed agriculture around the world, grain production increased by over 250%.<ref>{{cite journal |author1=Kindall, Henery W |author2=Pimentel, David|title=Constraints on the Expansion of the Global Food Supply |journal=Ambio. |volume=23 |issue=3 |date=May 1994 |url= http://dieoff.org/page36.htm}}</ref> The world population has grown by about four billion since the beginning of the Green Revolution and most believe that, without the Revolution, there would be greater ] and ] than the UN presently documents.<ref name="The limits of a Green Revolution" /><ref>" {{webarchive |url=https://web.archive.org/web/20161225150554/https://www.theguardian.com/environment/2008/feb/26/food.unitednations |date=25 December 2016 }}". The Guardian (2008-02-26).</ref>


The notion that space is limited has been decried by skeptics,<ref>{{Cite journal|last1=Young|first1=A.|year=1999|title=Is there Really Spare Land? A Critique of Estimates of Available Cultivable Land in Developing Countries|journal=Environment, Development and Sustainability|volume=1|pages=3–18|doi=10.1023/A:1010055012699|s2cid=153970029}}</ref> who point out that the Earth's population of roughly 6.8 billion people could comfortably be housed an area comparable in size to the state of ] in the United States (about {{convert|269000|sqmi|km2|2|disp=or|sigfig=6}}).<ref>{{cite web |title=Overpopulation: The Making of a Myth |url=http://overpopulationisamyth.com/overpopulation-the-making-of-a-myth#FAQ5 |access-date=13 February 2010 |archive-date=11 July 2017 |archive-url=https://web.archive.org/web/20170711020525/https://overpopulationisamyth.com/overpopulation-the-making-of-a-myth#FAQ5 |url-status=dead }}</ref> Critics and agricultural experts suggest changes to policies relating to ] or ] to make them more efficient would be more likely to resolve land issues and ] than focusing on reducing population alone.<ref name="Stone-2017" /><ref name="Nature-2010" />
The number of ] has surpassed the number who are undernourished. In a 2006 news story, ] reported, "There are an estimated 800 million undernourished people and more than a billion considered overweight worldwide." The U.S. has one of the highest rates of obesity in the world.<ref>{{cite web|url=http://www.msnbc.msn.com/id/14407969/ |title=Nearly 1 in 5 Chinese overweight or obese – Diet and nutrition |publisher=MSNBC |date=2006-08-18 |accessdate=2011-11-30}}</ref>
However, studies show that wealthy and educated people are far likelier to eat healthy food,<ref>{{cite web|url=http://articles.timesofindia.indiatimes.com/2012-09-13/diet/33424074_1_higher-levels-poor-countries-richer-countries |archive-url=https://archive.is/20130126072352/http://articles.timesofindia.indiatimes.com/2012-09-13/diet/33424074_1_higher-levels-poor-countries-richer-countries |archive-date=26 January 2013 |title= |dead-url=yes |accessdate=June 1, 2016 |df=dmy-all }}</ref> indicating obesity is a disease related to poverty and lack of education and excessive advertising of unhealthy eatables at cheaper cost, high in calories, with little nutritive value are consumed.<ref>{{cite web|url=http://frac.org/initiatives/hunger-and-obesity/are-low-income-people-at-greater-risk-for-overweight-or-obesity/ |title=Relationship Between Poverty and Overweight or Obesity « Food Research & Action Center |publisher=Frac.org |date= |accessdate=2013-09-22}}</ref><ref>{{cite web|url=http://www.dispatch.com/content/stories/local/2012/06/13/data-sobering-on-ohio-kids-poverty-obesity.html |title=Data sobering on Ohio kids’ poverty, obesity &#124; The Columbus Dispatch |publisher=Dispatch.com |date=2012-06-13 |accessdate=2013-09-22}}</ref>


], which threatens agricultural productivity, represents a global issue that some have linked to population growth.<ref>Brown, Lester R. and Halweil, Brian (23 September 1999). . Worldwatch Institute.</ref><ref>{{cite book|author=Fred Pearce|url=https://books.google.com/books?id=C0_q-90H1aAC|title=When the Rivers Run Dry: Water—The Defining Crisis of the Twenty-first Century|publisher=Beacon Press|year=2007|isbn=978-0-8070-8573-8}}</ref><ref>{{cite book|last=Worldwatch|first=The|url=https://books.google.com/books?id=1HEwh8nsljQC&q=Outgrowing+The+Earth:+The+Food+Security+Challenge+in+an+Age+of+Falling+Water+Tables+and+Rising+Temperature|title=Outgrowing the Earth: The Food Security Challenge in an Age of Falling Water Tables and Rising Temperatures: Books: Lester R. Brown|date=27 April 2012|publisher=Taylor & Francis |isbn=978-0393060706}}</ref> Colin Butler wrote in '']'' in 1994 that overpopulation also has economic consequences for certain countries due to resource use.<ref>{{cite journal |last1=Butler |first1=Colin David |date=5 March 1994 |title=Overpopulation, overconsumption, and economics |url=https://www.academia.edu/790276 |journal=The Lancet |volume=343 |issue=8897 |pages=582–584 |doi=10.1016/S0140-6736(94)91526-1 |pmid=7906334 |access-date=19 October 2022 |s2cid=30246584}}</ref>
]
The ] of the United Nations states in its report ''The State of Food Insecurity in the World 2006'', that while the number of undernourished people in the developing countries has declined by about three million, a smaller proportion of the populations of developing countries is undernourished today than in 1990–92: 17% against 20%. Furthermore, FAO's projections suggest that the proportion of hungry people in developing countries could be halved from 1990–92 levels to 10% by 2015. The FAO also states "We have emphasized first and foremost that reducing hunger is no longer a question of means in the hands of the global community. The world is richer today than it was ten years ago. There is more food available and still more could be produced without excessive upward pressure on prices. The knowledge and resources to reduce hunger are there. What is lacking is sufficient political will to mobilize those resources to the benefit of the hungry."<ref>{{dead link|date=December 2016 |bot=InternetArchiveBot |fix-attempted=yes }}. Food and Agriculture Organization of the United Nations (2006) {{ISBN|92-5-105580-7}} ftp.fao.org</ref>


=== Political systems and social conflict===
As of 2008, the price of grain has increased due to more farming used in ]s,<ref>{{cite web|url=http://www.sundayherald.com/news/heraldnews/display.var.2104849.0.2008_the_year_of_global_food_crisis.php |title=2008: The year of global food crisis |publisher=Sundayherald.com |date=8 March 2008 |accessdate=2011-11-30 |deadurl=yes |archiveurl=https://web.archive.org/web/20090822070637/http://www.sundayherald.com/news/heraldnews/display.var.2104849.0.2008_the_year_of_global_food_crisis.php |archivedate=22 August 2009 |df=dmy-all }}</ref> world ] at over $100 a barrel,<ref>{{cite web|url=http://www.csmonitor.com/2008/0118/p08s01-comv.html |title=The global grain bubble |publisher=Csmonitor.com |date=18 January 2008 |accessdate=2011-11-30}}</ref> global ],<ref>{{cite news|author=James Randerson, science correspondent |url=https://www.theguardian.com/science/2008/mar/07/scienceofclimatechange.food |title=Food crisis will take hold before climate change, warns chief scientist |work=The Guardian |location=UK |accessdate=2011-11-30 |date=7 March 2008}}</ref> ],<ref>{{cite news|author=John Vidal, environment editor |url=https://www.theguardian.com/environment/2007/nov/03/food.climatechange |title=Global food crisis looms as climate change and fuel shortages bite |work=The Guardian |location=UK |accessdate=2011-11-30 |date=3 November 2007}}</ref> loss of agricultural land to residential and industrial development,<ref>{{cite web|author=Walsoft |url=http://www.marketoracle.co.uk/Article3782.html |title=Experts: Global Food Shortages Could 'Continue for Decades' |publisher=Marketoracle.co.uk |date=2008-02-22 |accessdate=2011-11-30}}</ref><ref>{{cite web|author=Moya K. Mason |url=http://www.moyak.com/papers/urbanization-agriculture.html |title=Has Urbanization Caused a Loss to Agricultural Land? |publisher=Moyak.com |accessdate=2011-11-30}}</ref> and growing consumer demand in China and India<ref>{{cite news|last=Walt |first=Vivienne |url=http://www.time.com/time/world/article/0,8599,1717572,00.html |title=The World's Growing Food-Price Crisis |work=Time |date=2008-02-27 |accessdate=2011-11-30}}</ref><ref>{{cite news|url=http://news.bbc.co.uk/1/hi/world/7284196.stm |title=The cost of food: Facts and figures |publisher=BBC News |date=2008-10-16 |accessdate=2011-11-30}}</ref> ]s have recently taken place in many countries across the world.<ref>{{cite news|author=Jonathan Watts in Beijing |url=https://www.theguardian.com/world/2007/dec/04/china.business |title=Riots and hunger feared as demand for grain sends food costs soaring |work=The Guardian |location=UK |accessdate=2011-11-30 |date=2007-12-04}}</ref><ref>{{cite news|author=Roland Watson and Sam Fleming 30 November 2011 12:01&nbsp;am |url=http://www.timesonline.co.uk/tol/news/environment/article3500975.ece |title=Already we have riots, hoarding, panic: the sign of things to come? |work=The Times |location=UK |date=2009-06-25 |accessdate=2011-11-30}}</ref><ref>{{cite news|author=Julian Borger, diplomatic editor |url=https://www.theguardian.com/environment/2008/feb/26/food.unitednations |title=Feed the world? We are fighting a losing battle, UN admits |work=The Guardian |location=UK |accessdate=2011-11-30 |date=2008-02-26}}</ref> An epidemic of stem rust on wheat caused by race ] is currently spreading across Africa and into Asia and is causing major concern. A virulent wheat disease could destroy most of the world's main wheat crops, leaving millions to starve. The fungus has spread from Africa to ], and may already be in ] and Pakistan.<ref>{{cite news|author1=Robin McKie |author2=Xan Rice |url=https://www.theguardian.com/science/2007/apr/22/food.foodanddrink |title=Millions face famine as crop disease rages |work=The Guardian |location=UK |accessdate=2011-11-30 |date=2007-04-22}}</ref><ref name = NewSci>{{cite journal | url = http://environment.newscientist.com/channel/earth/mg19425983.700-billions-at-risk-from-wheat-superblight.html
It was speculated by ] in 1958 that ] is threatened by overpopulation, and could give rise to ] style governments.<ref>{{cite web | last1= Huxley | first1=Aldous | author-link1=Aldous Huxley | title=Brave New World Revisited: overpopulation | url=http://www.huxley.net/bnw-revisited/index.html#overpop | access-date=9 July 2014}} (A non-fiction book, with the entire book focused on the effects of human overpopulation on human affairs including both societal and individual concerns.)</ref> Physics professor ] at the ] warned in 2000 that overpopulation and the development of technology are the two major causes of the diminution of democracy.<ref>{{cite journal |last1=Bartlett |first1=Albert A.|author-link=Albert Allen Bartlett |date=2000 |title=Democracy Cannot Survive Overpopulation |url= |journal=] |volume=22 |issue=1 |pages=63–71 |doi=10.1023/A:1006681515521|s2cid=154695448}}</ref> However, over the last 200 years of population growth, the actual level of personal freedom has increased rather than declined.<ref name="Our World in Data" /> ] has argued population growth is a factor in numerous social issues, including ], ], ] and decaying infrastructure.<ref name="Bradshaw2021"/><ref>{{cite journal |last=Harte |first=John |date=2007 |title=Human population as a dynamic factor in environmental degradation |url= |journal=] |volume=28 |issue= 4–5|pages=223–236 |doi=10.1007/s11111-007-0048-3|s2cid=18611090 }}</ref> ] and others suggested in a 2017 paper that since the Second World War, countries with higher population growth rates experienced the most social conflict.<ref name="Bradshaw2021"/><ref>{{cite journal |url=https://www.nber.org/papers/w23322|title=Population and Civil War |last1=Acemoglu |first1=Daron |last2= Fergusson |first2=Leopoldo |last3=Johnson|first3=Simon|author-link1=Daron Acemoglu |date=2017 |website=] |series=Working Paper Series |publisher= |access-date=15 December 2021 |doi=10.3386/w23322|doi-access=free }}</ref>
|journal = New Scientist Magazine |title=Billions at risk from wheat super-blight |date=2007-04-03
|accessdate =19 April 2007 |issue= 2598 |pages = 6–7}}</ref><ref>{{cite web|url=http://www.alertnet.org/thenews/newsdesk/IRIN/8112190676ab183b80e80199f821ef93.htm |title=IRAN: Killer fungus threatens wheat production in western areas |publisher=Alertnet.org |accessdate=2011-11-30}}</ref>


Some advocates{{Who|date=November 2022}} have suggested societal problems such as hunger and mass unemployment are linked to overpopulation.<ref name="Moody2017" /><ref name="Ripple-2019" /><ref name="Bradshaw2021" />{{Verify source|date=November 2022}}
] will become more difficult to achieve as resources run out. Resources in danger of becoming depleted include ], ], ], ], and ].<ref>{{cite web|title='Peak Oil' and the German Government: Military Study Warns of a Potentially Drastic Oil Crisis|url=http://www.spiegel.de/international/germany/0,1518,715138,00.html|website=http://www.spiegel.de}}</ref><ref>" {{webarchive |url=https://web.archive.org/web/20161208111640/https://www.theguardian.com/global-development/2013/jul/06/food-supply-threat-water-wells-dry-up |date=8 December 2016 }}". ''The Guardian''. 6 July 2013.</ref> The British scientist ] predicted in 2009 that supplies of energy, food, and water will need to be increased by 50% to reach demand levels of 2030.<ref>" {{webarchive |url=https://web.archive.org/web/20161114162004/https://www.theguardian.com/science/2009/mar/18/perfect-storm-john-beddington-energy-food-climate |date=14 November 2016 }}". The Guardian. 18 March 2009.</ref><ref>" {{webarchive |url=https://web.archive.org/web/20161115024509/http://news.bbc.co.uk/2/hi/uk_news/7951838.stm |date=15 November 2016 }}". BBC News. 19 March 2009.</ref> According to the ] (FAO), food supplies will need to be increased by 70% by 2050 to meet projected demands.<ref>" {{webarchive |url=https://web.archive.org/web/20160310205117/http://www.finfacts.ie/irishfinancenews/article_1017966.shtml |date=10 March 2016 }}". Finfacts.com. 24 September 2009.</ref>


According to anthropologist ], the global ] system creates pressures for ]: "more people means more labour, cheaper labour, and more consumers."<ref>{{cite book|last=Hickel|first=Jason|author-link=Jason Hickel|title=Less is More: How Degrowth Will Save the World |year=2021|publisher=Windmill Books|pages=110–111|isbn=978-1786091215|quote= And of course capitalism itself creates pressures for population growth: more people means more labour, cheaper labour, and more consumers. These pressures filter into our culture, and even into national policy: countries like France and Japan are offering incentives to get women to have more children, to keep their economies growing.}}</ref> He and his colleagues have also demonstrated that capitalist elites throughout recent history have "used ] state policies to prevent women from practicing family planning" in order to grow the size of their workforce.<ref name="WorldDevelopment">{{cite journal |last1=Sullivan |first1=Dylan |last2=Hickel|first2=Jason |date=2023 |title=Capitalism and extreme poverty: A global analysis of real wages, human height, and mortality since the long 16th century|url= |journal=]|volume=161 |issue= |page=106026 |doi=10.1016/j.worlddev.2022.106026|access-date=|doi-access=free|quote=""}}</ref> Hickel has however argued that the cause of negative environmental impacts is resource extraction by wealthy countries.<ref>{{Cite book |last=Hickel |first=Jason |url=https://www.worldcat.org/oclc/1154101160 |title=Less is More: How Degrowth will Save the World |date=2021 |isbn=978-1-78609-121-5 |location=London |oclc=1154101160}}</ref>{{page needed|date=March 2023}}{{Verify source|date=March 2023}} He concludes that "we should not ignore the relationship between population growth and ecology, but we must not treat these as operating in a social and political vacuum."<ref name="WorldDevelopment"/>
====Africa====
The ''Population Reference Bureau'' in the US reported that the population of Sub-Saharan Africa - the poorest region in the continent - is rising faster than most of the rest of the world, and that "Rapid population growth makes it difficult for economies to create enough jobs to lift large numbers of people out of poverty." Seven of the 10 countries in Sub-Saharan Africa with the highest fertility rates also appear among the bottom 10 listed on the United Nations' Human Development Index.<ref>{{cite web|url=http://www.telegraph.co.uk/news/worldnews/africaandindianocean/10305000/Africas-population-to-double-to-2.4-billion-by-2050.html |title=Africa's population to double to 2.4 billion by 2050 |publisher=The Telegrapth|date=2013-09-12 |accessdate=2017-02-20}}</ref>


=== Epidemics and pandemics ===
] and ] kill nearly 6 million children a year, and more people are malnourished in ] this decade than in the 1990s, according to a report released by the ]. In sub-Saharan Africa, the number of malnourished people grew to 203.5 million people in 2000–02 from 170.4 million 10 years earlier says ''The State of Food Insecurity in the World'' report. In 2001, 46.4% of people in ] were living in extreme poverty.<ref>" {{webarchive |url=https://web.archive.org/web/20161227042142/http://www.independent.co.uk/news/world/politics/birth-rates-must-be-curbed-to-win-war-on-global-poverty-434387.html |date=27 December 2016 }}". The Independent. 31 January 2007.</ref>
A 2021 article in ''Ethics, Medicine and Public Health'' argued in light of the ] that ]s and ]s were made more likely by overpopulation, ], urbanization and encroachment into natural habitats.<ref>{{Cite journal|last1=Spernovasilis|first1=N.|last2=Markaki|first2=I.|last3=Papadakis|first3=M.|last4=Tsioutis|first4=C.|last5=Markaki|first5=L.|date=19 December 2021|title=Epidemics and pandemics: Is human overpopulation the elephant in the room?|journal=Ethics, Medicine, and Public Health|volume=19|page=100728|doi=10.1016/j.jemep.2021.100728|issn=2352-5525|pmc=8530531|pmid=34703871}}</ref>
] street crowds. ].]]


They both play a significant role impacting human populations, including widespread ], ], and ]. While they can leave a temporary loss of population, it is followed by significant loss and suffering. These events are not the sole reason for overpopulation, but lack of access to ] and reproductive contraptions, ] and ].<ref>{{Cite journal |last=Spernovasilis N, Markaki I, Papadakis M, Tsioutis C, Markaki L |date=19 December 2021 |title=Epidemics and pandemics: Is human overpopulation the elephant in the room? |journal=Ethics Med Public Health|volume=19 |page=100728 |doi=10.1016/j.jemep.2021.100728 |pmid=34703871 |pmc=8530531 }}</ref>
====Asia====
According to a 2004 article from the BBC, China, the world's most populous country, suffers from an "] surge". The article stated that, "Altogether, around 200 million people are thought to be overweight, 22.8% of the population, and 60 million (7.1%) obese".<ref>{{cite news| url=http://news.bbc.co.uk/2/hi/asia-pacific/3737162.stm |work=BBC News | title=Chinese concern at obesity surge | date=2004-10-12 | accessdate=20 May 2010}}</ref> More recent data indicate China's grain production peaked in the mid-1990s, due to increased extraction of ] in the North China plain.<ref>Brown, Lester R. (2002-09-08). . Greatlakesdirectory.org. Retrieved on 2012-08-29.</ref>


== Proposed solutions and mitigation measures ==
====Other countries====
Several strategies have been proposed to mitigate overpopulation.
Japan may face a food crisis that could reduce daily diets to the austere meals of the 1950s, believes a senior government adviser.<ref>{{cite web|url=http://www.theaustralian.news.com.au/story/0,20867,19420597-2703,00.html |archive-url=https://web.archive.org/web/20060611042316/http://www.theaustralian.news.com.au/story/0%2C20867%2C19420597-2703%2C00.html |archive-date=11 June 2006 |title=Japan warned of food shortage |dead-url=yes |accessdate=June 1, 2016 |df=dmy-all }}, The Australian</ref>


====Population as a function of food availability==== === Population planning ===
{{Main|Human population planning}}Several scientists (including ], ] and ]<ref name="Agencies-2006" /><ref>{{cite web|date=19 November 2009|title=Flannery calls for population inquiry|url=https://www.abc.net.au/news/2009-11-20/flannery-calls-for-population-inquiry/1149666|access-date=24 August 2021|website=www.abc.net.au|language=en-AU}}</ref>) proposed that humanity should work at stabilizing its absolute numbers, as a starting point towards beginning the process of reducing the total numbers. They suggested several possible approaches, including:<ref>{{citation|last1=Ehrlich|first1=Paul R|title=One with Nineveh: Politics, Consumption, and the Human Future|date=2004|pages=181–205 (chapter 6)|publisher=Island Press/Shearwater Books|last2=Ehrlich|first2=Anne H|author-link1=Paul R. Ehrlich|author-link2=Paul R. Ehrlich}}</ref><ref>{{citation|last1=Ehrlich|first1=Paul R.|title=The Stork and the Plow: The Equity Answer to the Human Dilemma|date=1995|publisher=Grosset/Putnam Books|last2=Ehrlich|first2=Anne H.|last3=Daily|first3=Gretchen C.|author-link1=Paul R. Ehrlich|author-link2=Paul R. Ehrlich|author-link3=Gretchen Daily}}</ref>
Thinkers from a wide range of academic fields and political backgrounds—including agricultural scientist David Pimentel,<ref name = "Hopfenberg and Pimentel">Hopfenberg, Russell and Pimentel, David, "Human Population Numbers as a Function of Food Supply", ''Environment, Development and Sustainability'', vol. 3, no. 1, March 2001, pp. 1–15</ref> behavioral scientist Russell Hopfenberg,<ref>{{Cite journal | last1 = Hopfenberg | first1 = R. | title = Human Carrying Capacity is Determined by Food Availability | doi = 10.1023/B:POEN.0000015560.69479.c1 | journal = Population and Environment | volume = 25 | issue = 2 | pages = 109–117 | year = 2003 | pmid = | pmc = }}</ref> right-wing anthropologist ],<ref>Abernathy, Virginia, ''Population Politics'' {{ISBN|0-7658-0603-7}}</ref> ecologist ],<ref>{{cite journal | last1 = Hardin | first1 = Garrett | year = 1974 | title = ] | url = | journal = Psychology Today | volume = 8 | issue = | pages = 38–43}}</ref> ecologist and anthropologist ], journalist ],<ref>{{cite interview |last=Manning |first=Richard |subjectlink=Richard Manning |interviewer=Sally Erickson and Timothy Scott Bennett |title= Richard Manning on the Green Revolution and the End of Cheap Oil |date= 7 Sep 2011 |work= YouTube|accessdate=15 Oct 2013|url=https://www.youtube.com/watch?v=SbUnGIxbvTM}}</ref> environmental biologist Alan D. Thornhill,<ref>''Food Production & Population Growth'', video with Daniel Quinn and Alan Thornhill</ref> cultural critic and writer ],<ref>Quinn, Daniel, '']'' Bantam/Turner, 1995, {{ISBN|0613080939}}</ref> and ] ],<ref>{{cite speech|title=On Modernity and the Technosphere|first=John|last=Zerzan|location=Binghamton University|date=April 2, 2008|url=https://www.youtube.com/watch?v=3I9QJVNas5k|at=See 38:35 to 39:00.}}</ref>—propose that, like all other animal populations, human populations predictably grow and shrink according to their available food supply, growing during an abundance of food and shrinking in times of scarcity.


* Improved access to ] and ]
Proponents of this theory argue that every time food production is increased, the population grows. Most human populations throughout history validate this theory, as does the overall current global population. Populations of ]s fluctuate in accordance with the amount of available food. The world human population began increasing after the ] and its increased food supply. This was, subsequent to the ], followed by even more severely accelerated population growth, which continues today. Often, wealthier countries send their surplus food resources to the aid of starving communities; however, proponents of this theory argue that this seemingly beneficial notion only results in further harm to those communities in the long run. Peter Farb, for example, has commented on the paradox that "intensification of production to feed an increased population leads to a still greater increase in population."<ref>Farb, Peter: 1978, ''Humankind''. Boston, Houghton Mifflin.</ref> Daniel Quinn has also focused on this phenomenon, which he calls the "]" (comparable, in terms of both escalation and potential catastrophe, to the ]).
* Reducing ], so that parents do not need to have many children to ensure at least some survive to adulthood.<ref>Lifeblood: How to Change the World One Dead Mosquito at a Time, Alex Perry p9</ref>
* Improving the ] in order to facilitate a departure from traditional sexual division of labour.
* ]<ref name="Ryerson 2010">{{cite book|last1=Ryerson|first1=William N.|title=The Post Carbon Reader: Managing the 21st Century's Sustainability Crises, "Ch.12: Population: The Multiplier of Everything Else"|date=2010|publisher=Watershed Media|isbn=978-0970950062|location=Healdsburg, Calif.|pages=153–174}}</ref>
* Creating small family "role models"<ref name="Ryerson 2010" />
* Secular cultures and societies.<ref name= "Schnabel 2021">{{cite journal|last1=Schnabel|first1=Landon|date=16 July 2021|title=Secularism and Fertility Worldwide|journal=Socius|volume=7|pages=1–18|doi=10.1177/23780231211031320|s2cid=237720715 |doi-access=free}}</ref>


There is good evidence from many parts of the world that when women and couples have the freedom to choose how many children to have, they tend to have smaller families.<ref>Engelman, R., 2012. Trusting women to end population growth. In: Cafaro, P., Crist, E. (Eds.), Life on the Brink: Environmentalists Confront Overpopulation. The University of Georgia Press, Athens and London, pp. 223–239.</ref><ref>Engelman, R., 2016. Nine population strategies to stop short of 9 billion. In: Washington, H., Twomey, P. (Eds.), A Future beyond Growth: Toward a Steady State Economy. Routledge, London, pp. 32–42.</ref><ref name="Crist-2019">{{Cite book |last=Crist |first=Eileen |url=http://dx.doi.org/10.7208/chicago/9780226596945.001.0001 |title=Abundant Earth |date=2019 |publisher=University of Chicago Press |doi=10.7208/chicago/9780226596945.001.0001 |isbn=978-0-226-59680-8|s2cid=134956670 }}</ref> &nbsp;
Critics of this theory point out that, in the modern era, birth rates are lowest in the ]s, which also have the highest access to food. In fact, some developed countries have both a diminishing population and an abundant food supply. The United Nations projects that the population of 51 countries or areas, including Germany, Italy, Japan, and most of the states of the former Soviet Union, is expected to be lower in 2050 than in 2005.{{citation needed|date=October 2014}} This shows that, limited to the scope of the population living within a single given political boundary, particular human populations do not always grow to match the available food supply. However, the global population as a whole still grows in accordance with the total food supply and many of these wealthier countries are major ''exporters'' of food to poorer populations, so that, "it is through exports from food-rich to food-poor areas (Allaby, 1984; Pimentel et al., 1999) that the population growth in these food-poor areas is further fueled."<ref name = "Hopfenberg and Pimentel"/>


Some scientists, such as Corey Bradshaw and Barry Brook, suggest that, given the "inexorable demographic momentum of the global human population," ] can be achieved more rapidly with a short term focus on technological and social innovations, along with reducing consumption rates, while treating population planning as a long-term goal.<ref>{{cite news |first=Matt |last=McGrath |url=https://www.bbc.com/news/science-environment-29788754 |title=Population controls 'will not solve environment issues' |publisher=BBC |date=27 October 2014 |access-date=16 December 2021}}</ref><ref>{{cite journal |title=Human population reduction is not a quick fix for environmental problems |last1=Bradshaw |first1=Corey J. A. |last2=Brook |first2=Barry W. |journal=] |volume=111 |issue=46 |pages=16610–16615 |doi=10.1073/pnas.1410465111 |pmid=25349398 |year=2014 |pmc=4246304 |bibcode=2014PNAS..11116610B |doi-access=free}}</ref>
Regardless of criticisms against the theory that population is a function of food availability, the ] is, on the global scale, undeniably increasing,<ref>] (1996). '']'', pp. 304–305, Random House Publishing Group, {{ISBN|0553379011}}.</ref> as is the net quantity of human food produced — a pattern that has been true for roughly 10,000 years, since the human development of agriculture. The fact that some affluent countries demonstrate negative population growth fails to discredit the theory as whole, since the world has become a ] with food moving across national borders from areas of abundance to areas of scarcity. Hopfenberg and Pimentel's findings support both this<ref name = "Hopfenberg and Pimentel"/> and Quinn's direct accusation that "First World farmers are fueling the Third World population explosion."<ref>Quinn, Daniel: "The Question (ID Number 122)", Retrieved October 2014 from {{cite web|url=http://www.ishmael.org/Interaction/QandA/Detail.CFM?Record%3D122 |title=Archived copy |accessdate=2014-10-18 |deadurl=no |archiveurl=https://web.archive.org/web/20160304064622/http://ishmael.org/interaction/qanda/detail.cfm?record=122 |archivedate=4 March 2016 |df=dmy }}.</ref> Additionally, the hypothesis is not so simplistic as to be rejected by any single case study, as in Germany's recent population trends; clearly other factors are at work to limit the population in wealthier areas: ] access, educational programs, cultural norms and, most influentially, differing economic realities from nation to nation.


However, most scientists believe that achieving genuine sustainability is a long-term project, and that addressing population and consumption levels are both essential to achieving it.
====As a result of water deficits====
], which are already spurring heavy grain imports in numerous smaller countries, may soon do the same in larger countries, such as China or India, if technology is not used.<ref>{{cite web|url=http://www.atimes.com/atimes/South_Asia/HG21Df01.html |title=Asia Times Online :: South Asia news – India grows a grain crisis |publisher=Atimes.com |date=21 July 2006 |accessdate=2011-11-30}}</ref> The water tables are falling in scores of countries (including Northern China, the US, and India) owing to widespread ] beyond ] yields.<ref name=Ehrlich-Books/> Other countries affected include Pakistan, ], and Mexico. This overdrafting is already leading to ] and cutbacks in grain harvest. Even with the overpumping of its ], China has developed a grain deficit. This effect has contributed in driving grain prices upward. Most of the 3 billion people projected to be added worldwide by mid-century will be born in countries already experiencing ]. ] is also considered a viable and effective solution to the problem of water shortages.<ref name = "ejpress-water">{{cite web|url=http://www.ejpress.org/article/4873 |title=EJP &#124; News &#124; France &#124; French-run water plant launched in Israel |publisher=Ejpress.org |date=2005-12-28 |accessdate=2011-11-30}}</ref><ref name="edie-distinct">{{cite web|url=http://www.edie.net/news/news_story.asp?id=11402&channel=0 |title=Black & Veatch-Designed Desalination Plant Wins Global Water Distinction |publisher=Edie.net |date=4 May 2006 |accessdate=2011-11-30 |deadurl=yes |archiveurl=https://web.archive.org/web/20100324144203/http://www.edie.net/news/news_story.asp?id=11402&channel=0 |archivedate=24 March 2010 |df= }}</ref>


In 1992, more than 1700 scientists from around the world signed onto a "]," including a majority of the living Nobel prize-winners in the sciences.<ref name="www.ucsusa.org">{{Cite web |title=1992 World Scientists' Warning to Humanity {{!}} Union of Concerned Scientists |url=https://www.ucsusa.org/resources/1992-world-scientists-warning-humanity |access-date= |website=www.ucsusa.org |language=en}}</ref> "The earth is finite," they wrote. "Its ability to absorb wastes and destructive effluent is finite. Its ability to provide food and energy is finite. Its ability to provide for growing numbers of people is finite. And we are fast approaching many of the earth's limits."<ref name="www.ucsusa.org" /> The warning noted:<blockquote>Pressures resulting from unrestrained population growth put demands on the natural world that can overwhelm any efforts to achieve a sustainable future. If we are to halt the destruction of our environment, we must accept limits to that growth.<ref name="www.ucsusa.org" /> </blockquote>Two of the five areas where the signatories requested immediate action were "stabilize population" and "ensure sexual equality, and guarantee women control over their own reproductive decisions."<ref name="www.ucsusa.org" />
After China and India, there is a second tier of smaller countries with large water deficits – ], Egypt, ], Mexico, and Pakistan. Four of these already import a large share of their grain. Only Pakistan remains self-sufficient. But with a population expanding by 4 million a year, it will also soon turn to the world market for grain.<ref name="The Food Bubble Economy"/>


In a follow-up message 25 years later, ] and colleagues issued the "World Scientists' Warning to Humanity: A Second Notice."<ref>{{Cite journal |last1=Ripple |first1=William J. |last2=Wolf |first2=Christopher |last3=Newsome |first3=Thomas M. |last4=Galetti |first4=Mauro |last5=Alamgir |first5=Mohammed |last6=Crist |first6=Eileen |last7=Mahmoud |first7=Mahmoud I. |last8=Laurance |first8=William F. |date=13 November 2017 |title=World Scientists' Warning to Humanity: A Second Notice |url=http://dx.doi.org/10.1093/biosci/bix125 |journal=BioScience |volume=67 |issue=12 |pages=1026–1028 |doi=10.1093/biosci/bix125 |issn=0006-3568|hdl=11336/71342 |hdl-access=free }}</ref> This time more than 15,000 scientists from around the world signed on.<ref>{{Cite journal |last1=Ripple |first1=William J |last2=Wolf |first2=Christopher |last3=Galetti |first3=Mauro |last4=Newsome |first4=Thomas M |last5=Green |first5=Tom L |last6=Alamgir |first6=Mohammed |last7=Crist |first7=Eileen |last8=Mahmoud |first8=Mahmoud I |last9=Laurance |first9=William F |date=7 March 2018 |title=The Role of Scientists' Warning in Shifting Policy from Growth to Conservation Economy |url=http://dx.doi.org/10.1093/biosci/biy009 |journal=BioScience |volume=68 |issue=4 |pages=239–240 |doi=10.1093/biosci/biy009 |issn=0006-3568|hdl=11449/166092 |hdl-access=free }}</ref> "We are jeopardizing our future by not reining in our intense but geographically and demographically uneven material consumption and by not perceiving continued rapid population growth as a primary driver behind many ecological and even societal threats," they wrote.<ref name="Ripple-2017">{{Cite journal |last1=Ripple |first1=William J. |last2=Wolf |first2=Christopher |last3=Newsome |first3=Thomas M. |last4=Galetti |first4=Mauro |last5=Alamgir |first5=Mohammed |last6=Crist |first6=Eileen |last7=Mahmoud |first7=Mahmoud I. |last8=Laurance |first8=William F. |date=13 November 2017 |title=World Scientists' Warning to Humanity: A Second Notice |url=http://dx.doi.org/10.1093/biosci/bix125 |journal=BioScience |volume=67 |issue=12 |pages=1026 |doi=10.1093/biosci/bix125 |issn=0006-3568|hdl=11336/71342 |hdl-access=free }}</ref> "By failing to adequately limit population growth, reassess the role of an economy rooted in growth, reduce greenhouse gases, incentivize renewable energy, protect habitat, restore ecosystems, curb pollution, halt defaunation, and constrain invasive alien species, humanity is not taking the urgent steps needed to safeguard our imperilled biosphere."<ref name="Ripple-2017" /> This second scientists’ warning urged attention to both excessive consumption and continued population growth. Like its predecessor, it did not specify a definite global human carrying capacity. But its call to action included "estimating a scientifically defensible, sustainable human population size for the long term while rallying nations and leaders to support that vital goal."<ref>{{Cite journal |last1=Ripple |first1=William J. |last2=Wolf |first2=Christopher |last3=Newsome |first3=Thomas M. |last4=Galetti |first4=Mauro |last5=Alamgir |first5=Mohammed |last6=Crist |first6=Eileen |last7=Mahmoud |first7=Mahmoud I. |last8=Laurance |first8=William F. |date=13 November 2017 |title=World Scientists' Warning to Humanity: A Second Notice |url=http://dx.doi.org/10.1093/biosci/bix125 |journal=BioScience |volume=67 |issue=12 |pages=1028 |doi=10.1093/biosci/bix125 |issn=0006-3568|hdl=11336/71342 |hdl-access=free }}</ref> &nbsp;
===Land===
]


Subsequent scientists' calls to action have also included calls for population planning. The 2020 "World Scientists' Warning of a Climate Emergency" stated: "Economic and population growth are among the most important drivers of increases in ] emissions from fossil fuel combustion." "Therefore," the study noted: "we need bold and drastic transformations regarding economic and population policies."<ref>{{Cite journal |last1=Ripple |first1=William J |last2=Wolf |first2=Christopher |last3=Newsome |first3=Thomas M |last4=Barnard |first4=Phoebe |last5=Moomaw |first5=William R |date=2020 |title=World Scientists' Warning of a Climate Emergency |url=https://doi.org/10.1093/biosci/biz088 |journal=BioScience |volume=70 |issue=1 |pages=10 |doi=10.1093/biosci/biz088 |issn=0006-3568|hdl=2445/151800 |hdl-access=free }}</ref> "The world population must be stabilized—and, ideally, gradually reduced,"<ref>{{Cite journal |last1=Ripple |first1=William J |last2=Wolf |first2=Christopher |last3=Newsome |first3=Thomas M |last4=Barnard |first4=Phoebe |last5=Moomaw |first5=William R |date=2020 |title=World Scientists' Warning of a Climate Emergency |url=https://doi.org/10.1093/biosci/biz088 |journal=BioScience |volume=70 |issue=1 |pages=11 |doi=10.1093/biosci/biz088 |issn=0006-3568|hdl=2445/151800 |hdl-access=free }}</ref> it concluded, implying that humanity is overpopulated given current and expected levels of resource use and waste generation.
The World Resources Institute states that "Agricultural conversion to croplands and managed ]s has affected some 3.3 billion – roughly 26 percent of the land area. All totaled, agriculture has displaced one-third of ] and ]s and one-quarter of natural grasslands."<ref>{{cite web
|url=http://earthtrends.wri.org/features/view_feature.php?theme=8&fid=34 |title= Domesticating the World: Conversion of Natural Ecosystems |publisher=World Resources Institute |date=September 2000}}</ref><ref>{{cite web |url=http://earthtrends.wri.org/features/view_feature.php?theme=9&fid=8 |title=Grasslands in Pieces: Modification and Conversion Take a Toll |publisher=World Resources Institute |date=December 2000}}</ref> Forty percent of the land area is under conversion and fragmented; less than one quarter, primarily in the Arctic and the deserts, remains intact.<ref>{{cite web|url=http://www.globio.info/impacts/ |archiveurl=https://web.archive.org/web/20070630131304/http://www.globio.info/impacts/ |archivedate=2007-06-30 |title=GLOBIO, an initiative of the United Nations Environment Programme (Archive) |publisher=Web.archive.org |date=30 June 2007 |accessdate=2011-11-30}}</ref> Usable land may become less useful through ], ], ], ], and ]. ] may cause flooding of many of the most productive agricultural areas.<ref>John Houghton, ''Global Warming: The Complete Briefing'', Cambridge University Press, 2009 {{ISBN|978-0-521-70916-3}}</ref> The development of energy sources may also require large areas, for example, the building of ]. Thus, available useful land may become a limiting factor. By most estimates, at least half of cultivable land is already being farmed, and there are concerns that the remaining reserves are greatly overestimated.<ref>{{Cite journal | last1 = Young | first1 = A. | journal = Environment, Development and Sustainability | volume = 1 |title=Is there Really Spare Land? A Critique of Estimates of Available Cultivable Land in Developing Countries| pages = 3–2 | doi = 10.1023/A:1010055012699 | year = 1999 | pmid = | pmc = }}</ref>


A follow-up scientists’ warning on climate change in 2021 reiterated the need to plan and limit human numbers to achieve sustainability, proposing as a goal "stabilizing and gradually reducing the population by providing voluntary family planning and supporting education and rights for all girls and young women, which has been proven to lower fertility rates."<ref>{{Cite journal |last1=Ripple |first1=William J |last2=Wolf |first2=Christopher |last3=Newsome |first3=Thomas M |last4=Gregg |first4=Jillian W |last5=Lenton |first5=Timothy M |last6=Palomo |first6=Ignacio |last7=Eikelboom |first7=Jasper A J |last8=Law |first8=Beverly E |last9=Huq |first9=Saleemul |last10=Duffy |first10=Philip B |last11=Rockström |first11=Johan |date=28 July 2021 |title=World Scientists' Warning of a Climate Emergency 2021 |url=http://dx.doi.org/10.1093/biosci/biab079 |journal=BioScience |volume=71 |issue=9 |pages=894–898 |doi=10.1093/biosci/biab079 |issn=0006-3568|hdl=10871/126814 |hdl-access=free }}</ref>
High ] vegetables like potatoes and lettuce{{Citation needed|date=October 2008}} <!--Lettuce is high yield?--> use less space on inedible plant parts, like stalks, husks, vines, and inedible leaves. New varieties of selectively bred and ] plants have larger edible parts (fruit, vegetable, grain) and smaller inedible parts; however, many of these gain of agricultural technology are now historic, and new advances are more difficult to achieve. With new technologies, it is possible to grow crops on some marginal land under certain conditions. ] could theoretically increase available area. ] and food from bacteria and fungi, like ], may allow the growing of food without having to consider land quality, climate, or even available sunlight, although such a process may be very energy-intensive. Some argue that not all arable land will remain productive if used for agriculture because some ] can only be made to produce food by unsustainable practices like ] agriculture. Even with the modern techniques of agriculture, the sustainability of production is in question.


==== Family planning ====
Some countries, such as the ] and particularly the Emirate of ] have constructed large artificial islands, or have created large dam and dike systems, like the Netherlands, which ] from the sea to increase their total land area.<ref>{{cite news|last=Tagliabue|first=John|title=The Dutch seek to claim more land from the sea|url=https://www.nytimes.com/2008/11/07/world/europe/07iht-journal.1.17618884.html|accessdate=9 February 2017|work=]|date=7 November 2008}}</ref><ref>{{cite news|last=Shepard|first=Wade|title="The gift from the sea": through land reclamation, China keeps growing and growing|url=http://www.citymetric.com/skylines/gift-sea-through-land-reclamation-china-keeps-growing-and-growing-1350|accessdate=9 February 2017|work=CityMetric|publisher=]|date=25 August 2015}}</ref> Some scientists have said that in the future, densely populated cities will use ] to grow food inside skyscrapers.<ref name = "BBC-nyc">{{cite news| url=http://news.bbc.co.uk/2/hi/americas/6752795.stm |work=BBC News | title=Vertical farming in the big Apple | date=19 June 2007 | accessdate=20 May 2010 | first=Jeremy | last=Cooke}}</ref> The notion that space is limited has been decried by skeptics, who point out that the Earth's population of roughly 6.8 billion people could comfortably be housed an area comparable in size to the state of Texas, in the United States (about {{convert|269000|sqmi|km2|2|disp=or|sigfig=6}}).<ref>{{cite web|url=http://overpopulationisamyth.com/overpopulation-the-making-of-a-myth#FAQ5|title=Overpopulation: The Making of a Myth|accessdate=13 February 2010}}</ref> However, the impact of humanity extends over a far greater area than that required simply for housing.
{{main|Family planning|Reproductive rights|Birth control}}
] placard in ]. It depicts negative effects of having more children than people can care for.]]


Education and ] and giving access to ] and contraception have a demonstrated impact on reducing birthrates.<ref name="The Economist-2019">{{Cite news|date=2 February 2019|title=Thanks to education, global fertility could fall faster than expected|newspaper=The Economist|url=https://www.economist.com/international/2019/02/02/thanks-to-education-global-fertility-could-fall-faster-than-expected|access-date=4 August 2021|issn=0013-0613}}</ref> Many studies conclude that ] reduces the number of children they have.<ref name="The Economist-2019" /> One option according to some activists is to focus on education about ] and ] methods, and to make birth-control devices like ], ] and ]s easily available. Worldwide, nearly 40% of ] (some 80 million unintended pregnancies each year).<ref>" {{webarchive |url=https://web.archive.org/web/20120523114015/https://www.google.com/hostednews/afp/article/ALeqM5gevGOq7Vctd1FmJkzO3gapTqX4ZA |date=23 May 2012 }}". ] (21 September 2009).</ref> An estimated 350 million women in the poorest countries of the world either did not want their last child, do not want another child or want to space their pregnancies, but they lack access to information, affordable means and services to determine the size and spacing of their families{{When|date=February 2022}}. In the ], some 514,000 women die annually of complications from pregnancy and abortion,<ref>"". United Nations Population Fund (UNFPA).</ref> with 86% of these deaths occurring in the ] region and South Asia.<ref>" {{webarchive |url=https://web.archive.org/web/20131031223858/http://www.who.int/mediacentre/news/releases/2007/pr56/en/index.html |date=31 October 2013 }}". ] (12 October 2007).</ref> Additionally, 8 million infants die, many because of ] or preventable diseases, especially from lack of access to clean drinking water.<ref>{{cite news| url=http://findarticles.com/p/articles/mi_m1571/is_46_17/ai_80774574 | work=Insight on the News | title=Q: should the United Nations support more family-planning services for poor countries? | first=Werner | last=Fornos | date=10 December 2001}}</ref>
===Fossil fuels===
{{See also|Peak oil}}
]'s prediction of world petroleum production rates. Modern agriculture is totally reliant on petroleum energy.]]
Population optimists have been criticized for failing to take into account the depletion of the petroleum required for the production of ]s and fuel for transportation, as well as other ]s.<ref>" {{webarchive |url=https://web.archive.org/web/20160908194714/http://www.independent.co.uk/news/science/world-oil-supplies-are-set-to-run-out-faster-than-expected-warn-scientists-6262621.html |date=8 September 2016 }}". ''The Independent''. 14 June 2007.</ref> In his 1992 book '']'', ] wrote, "... it ought to be possible to establish a coordinated global program to accomplish the strategic goal of completely eliminating the internal combustion engine over, say, a twenty-five-year period..."<ref>{{cite web|url=http://www.crossroad.to/articles2/Gore.html |title=Al Gore's Vision of Global Salvation |publisher=Crossroad.to |accessdate=2011-11-30}}</ref> Approximately half of the oil produced in the United States is refined into gasoline for use in internal combustion engines.<ref>{{cite web|url=http://tonto.eia.doe.gov/energyexplained/index.cfm?page=gasoline_home |title=Gasoline – Energy Explained, Your Guide To Understanding Energy |publisher=Tonto.eia.doe.gov |accessdate=2011-11-30}}</ref>


] and their ] in particular are issues regarded to have vital importance in the debate.<ref name="Webb" /> Anthropologist ] asserts that a nation's population growth rapidly declines - even within a single generation - when policies relating to women's health and reproductive rights, children's health (to ensure parents they will survive to adulthood), and expanding education and economic opportunities for girls and women are implemented.<ref>{{cite book|last=Hickel|first=Jason|author-link=Jason Hickel|title=Less is More: How Degrowth Will Save the World |year=2021|publisher=Windmill Books|page=111|isbn=978-1786091215}}</ref>
The report ''Peaking of World Oil Production: Impacts, Mitigation, and Risk Management'', commonly referred to as the ], was created by request for the ] and published in February 2005.<ref name="hirsch_report">{{cite web
|url=http://www.netl.doe.gov/publications/others/pdf/Oil_Peaking_NETL.pdf
|title= Peaking Of World Oil Production: Impacts, Mitigation, & Risk Management
|first= Robert L.
|last= Hirsch
|first2= Roger
|last2= Bezdek
|first3= Robert
|last3= Wendling
|date=February 2005
|publisher= Science Applications International Corporation/U.S.Department of Energy, National Energy Technology Laboratory
|format=PDF
|accessdate=28 November 2009}}</ref>
Some information was updated in 2007.<ref>{{cite web
|url=http://netl.doe.gov/File%20Library/Research/Energy%20Analysis/Publications/DOE-NETL-2007-1263-PeakingWorldOilProd-RecentForecasts.pdf|title= Peaking of World Oil Production: Recent Forecasts
|first= Robert L.
|last= Hirsch
|date=February 2007
|publisher= Science Applications International Corporation/U.S.Department of Energy, National Energy Technology Laboratory
|format=PDF
|accessdate=19 February 2015}}</ref>
It examined the time frame for the occurrence of ], the necessary mitigating actions, and the likely impacts based on the timeliness of those actions. It concludes that world oil peaking is going to happen, and will likely be abrupt. Initiating a mitigation crash program 20 years before peaking appears to offer the possibility of avoiding a world liquid fuels shortfall for the forecast period.


A 2020 paper by ] and other scientists argued in favor of population policies that could advance ] (such as by abolishing ], expanding family planning services and reforms that improve education for women and girls) and at the same time mitigate the impact of population growth on climate change and biodiversity loss.<ref name="WolfRipple2021"/> In a 2022 warning on population published by '']'', Ripple, Ehrlich and other scientists appealed to families around the world to have no more than one child and also urged policy-makers to improve education for young females and provide high-quality family-planning services.<ref name="Crist2022">{{cite journal |last1=Crist|first1=Eileen|last2=Ripple|first2=William J.|last3= Ehrlich|first3=Paul R.|last4=Rees|first4=William E. |last5=Wolf|first5=Christopher |date=2022 |title=Scientists' warning on population|url=https://scientistswarning.forestry.oregonstate.edu/sites/default/files/Crist2022.pdf|journal=Science of the Total Environment|volume=845 |issue=|page=157166 |doi=10.1016/j.scitotenv.2022.157166|pmid= 35803428|s2cid=250387801 }}</ref>
Optimists counter that fossil fuels will be sufficient until the development and implementation of suitable replacement technologies—such as nuclear power or various sources of ]—occurs.<ref>{{cite web|url=http://economics.about.com/cs/macroeconomics/a/run_out_of_oil.htm |title=We Will Never Run Out of Oil |publisher=Economics.about.com |date=27 June 2011 |accessdate=2011-11-30}}</ref> Methods of manufacturing fertilizers from garbage, ], and agricultural waste by using ] have been discovered.<ref>{{cite web|last=Lemley |first=Brad |url=http://discovermagazine.com/2003/may/featoil/ |title=Anything Into Oil &#124; Alternative Energy |publisher=DISCOVER Magazine |date=1 May 2003 |accessdate=2011-11-30}}</ref><ref>{{cite web|last=Lemley |first=Brad |url=http://discovermagazine.com/2006/apr/anything-oil/ |title=Anything Into Oil &#124; Alternative Energy |publisher=DISCOVER Magazine |date=2 April 2006 |accessdate=2011-11-30}}</ref>


===Wealth and poverty=== ===Extraterrestrial settlement===
{{Excerpt|Space colonization#Alleviating overpopulation and resource demand}}
{{Main article|Demographic transition|Income and fertility}}
]


===Urbanization===
The United Nations indicates that about 850 million people are ] or ],<ref name="FAO-Italy">Food and Agriculture Organization of the United Nations (2001). {{webarchive |url=https://web.archive.org/web/20161201161538/http://www.fao.org/docrep/003/y1500e/y1500e00.htm |date=1 December 2016 }}. FAO, {{ISBN|92-5-104628-X}}</ref> and 1.1 billion people ] to safe ].<ref name = "Shiklomanov-11-32">{{Cite journal | last1 = Shiklomanov | first1 = I. A. | doi = 10.1080/02508060008686794 | title = Appraisal and Assessment of World Water Resources | journal = Water International | volume = 25 | pages = 11–32 | year = 2000 | pmid = | pmc = }}</ref> Since 1980, the global economy has grown by 380 percent, but the number of people living on less than 5 US dollars a day increased by more than 1.1 billion.<ref> {{webarchive |url=https://web.archive.org/web/20161201174824/https://www.theguardian.com/global-development-professionals-network/2015/sep/23/developing-poor-countries-de-develop-rich-countries-sdgs |date=1 December 2016 }}. ''].'' September 23, 2015.</ref>
{{See|New Urbanism|Sustainable urbanism}}
Despite the increase in population density within cities (and the emergence of megacities), ] Data Corp. states in its reports that urbanization may be the best compromise in the face of global population growth.<ref>{{cite news|url=http://news.bbc.co.uk/2/hi/in_depth/6244496.stm |title=UN Habitat calling urban living 'a good thing |work=BBC News |date=27 June 2007 |access-date=30 November 2011}}</ref> Cities concentrate human activity within limited areas, limiting the breadth of environmental damage.<ref>{{cite web|url=http://www.michellenijhuis.com/ |title=National Geographic Magazine; Special report 2008: Changing Climate (Village Green-article by Michelle Nijhuis) |publisher=Michellenijhuis.com |date=29 September 2011 |access-date=30 November 2011}}</ref> UN Habitat says this is only possible if ] is significantly improved.<ref>{{cite web|url=http://www.unhabitat.org/content.asp?cid=2523&catid=5&typeid=6&subMenuId=0 |title=UN Habitat calling to rethink urban planning |publisher=Unhabitat.org |access-date=30 November 2011 |url-status=dead |archive-url=https://web.archive.org/web/20110807191706/http://www.unhabitat.org/content.asp?cid=2523&catid=5&typeid=6&subMenuId=0 |archive-date=7 August 2011 }}</ref>


] proposed in '']'' that rhetoric supporting the increase of city density is a means of avoiding dealing with what he views as the root problem of overpopulation and has been promoted by what he views as the same interests that have allegedly profited from population increase (such as property developers, the banking system which invests in property development, industry, and municipal councils).<ref>Ehrlich, Population Bomb 1968 p.152-p.53</ref> Subsequent authors point to ] as driving governments seek city growth and expansion at any cost, disregarding the impact it might have on the environment.<ref>{{cite news|url=https://www.nationalobserver.com/2018/03/05/news/david-suzuki-fires-death-zone-trudeau-weaver-and-broken-system|title=David Suzuki fires off from the 'death zone' at Trudeau, Weaver and a broken system|date=5 March 2018|website=National Observer}}</ref>
The UN ] of 1997 states: "During the last 15–20 years, more than 100 developing countries, and several Eastern European countries, have suffered from disastrous growth failures. The reductions in ] have been deeper and more long-lasting than what was seen in the industrialised countries during the ]. As a result, the income for more than one billion people has fallen below the level that was reached 10, 20 or 30 years ago". Similarly, although the proportion of "starving" people in ] has decreased, the absolute number of starving people has increased due to population growth. The percentage dropped from 38% in 1970 to 33% in 1996 and was expected to be 30% by 2010.<ref name=autogenerated1 /> But the region's population roughly doubled between 1970 and 1996. To keep the numbers of starving constant, the percentage would have dropped by more than half.<ref name = "ecosystems-#3"/><ref>{{cite web|url=http://www.greenfacts.org/en/ecosystems/millennium-assessment-3/3-human-wellbeing-poverty.htm#3p0 |title=3. How have ecosystem changes affected human well-being and poverty alleviation? |publisher=Greenfacts.org |date=2011-10-17 |accessdate=2011-11-30}}</ref>


==Criticism==
] vs. ], 2015.<ref>{{cite web|url=https://www.cia.gov/library/publications/the-world-factbook/fields/2127.html|title=Field Listing: Total Fertility Rate|website=]|accessdate=2016-04-24}}</ref>
{{See also|Population ethics|Economic consequences of population decline}}
<ref>{{cite web|url=https://www.cia.gov/library/publications/resources/the-world-factbook/rankorder/2004rank.html|title=Country Comparison: GDP – Per Capita (PPP)|website=]|accessdate=2016-04-24}}</ref>]]
].<ref> in ''World Population Prospects, the 2010 Revision''. United Nations, Department of Economic and Social Affairs, Population Division (2011)</ref>]]
As of 2004, there were 108 countries in the world with more than five million people. All of these in which women have, on the average, more than 4 children in their lifetime, have a per capita GDP of less than $5000. Only in two countries with per capita GDP above ~$15,000 do women have, on the average, more than 2 children in their lifetime: these are Israel and Saudi Arabia, with average lifetime births per woman between 2 and 4.
The concept of human overpopulation, and its attribution as a cause of environmental issues, are controversial.<ref name="Deutsche Welle">{{cite web|title=What fewer people on the planet would mean for the environment {{!}} DW {{!}} 31 August 2020|url=https://www.dw.com/en/overpopulation-climate-change-emissions/a-54725928|access-date=30 July 2021|website=Deutsche Welle|language=en-GB}}</ref><ref name="Piper-2019" /><ref name="Dyett-2019">{{Cite journal|last1=Dyett|first1=Jordan|last2=Thomas|first2=Cassidy|date=18 January 2019|title=Overpopulation Discourse: Patriarchy, Racism, and the Specter of Ecofascism|url=https://brill.com/view/journals/pgdt/18/1-2/article-p205_16.xml|journal=Perspectives on Global Development and Technology|language=en|volume=18|issue=1–2|pages=205–224|doi=10.1163/15691497-12341514|s2cid=159217740|issn=1569-1500}}</ref><ref name="Kaneda-2014">{{cite web|last=Roberts|first=David|date=26 September 2017|title="I'm an environmental journalist, but I never write about overpopulation. Here's why."|url=https://www.vox.com/energy-and-environment/2017/9/26/16356524/the-population-question|access-date=30 July 2021|website=Vox|language=en}}</ref><ref name="www.newstatesman.com-2020">{{cite web|title=David Attenborough's claim that humans have overrun the planet is his most popular comment|url=https://www.newstatesman.com/politics/environment/2020/11/david-attenborough-s-claim-humans-have-overrun-planet-his-most-popular|access-date=3 August 2021|website=www.newstatesman.com|date=4 November 2020|language=en}}</ref>


Some critics, including ], ], ] and Betsy Hartmann, refer to overpopulation as a myth.<ref name="Pearce-2010" /><ref name="Nature 12-1-2015" /><ref name="Hartmann">{{Cite book|last=Hartmann|first=Betsy|year=2016|orig-year=1987|title=Reproductive Rights and Wrongs: The Global Politics of Population Control|place=], ]|publisher=]|edition=3rd|page=26|isbn=978-1608467334}}</ref><ref name="The Independent-2011" /><ref name="Rao-1994">{{Cite journal|last=Rao|first=Mohan|date=1994|title=An Imagined Reality: Malthusianism, Neo-Malthusianism and Population Myth|url=https://www.jstor.org/stable/4400725|journal=Economic and Political Weekly|volume=29|issue=5|pages=PE40–PE52|jstor=4400725|issn=0012-9976}}</ref> Predicted exponential population growth or any "population explosion" did not materialise; instead, population growth slowed.<ref name="archive.is-2020-2" /><ref name="The Wire" /> Critics suggest that enough resources are available to support projected population growth, and that ] are not attributable to overpopulation.<ref name="Alberro" /><ref name="www.newstatesman.com-2020" /><ref name="The Independent-2011">{{cite news|date=18 January 2011|title=Dominic Lawson: The population timebomb is a myth The doom-sayers are becoming more fashionable just as experts are coming to the view it has all been one giant false alarm|work=The Independent|location=UK|url=https://www.independent.co.uk/opinion/commentators/dominic-lawson/dominic-lawson-the-population-timebomb-is-a-myth-2186968.html|access-date=30 November 2011}}</ref>
As their income increases, women are ] and tend to have fewer "quantity kids", as in two in place of six.<ref>{{cite video|people=Brand, Stewart|title=Lecture Series presented by KPMG – Whole Earth Discipline|url=http://www.q2cfestival.com/play.php?lecture_id=8030|date=2009-10-24|publisher=Perimeter Institute, Quantum to Cosmos (Q2C) Festival|location=Waterloo, Ontario, Canada|accessdate=2009-10-25|time=50:30}}</ref>


According to libertarian think tank the ], both the idea of overpopulation and the alleged depletion of resources are myths; most resources are now more abundant than a few decades ago, thanks to technological progress.<ref name="fraserinstitute.org">{{cite web |last1=Peron |first1=Jim |title=Exploding Population Myths |url=https://www.fraserinstitute.org/sites/default/files/ExplodingPopulationMyths.pdf |website=frasterinstitute.org |publisher=The Fraser Institute |access-date=19 October 2022 |archive-url=https://web.archive.org/web/20211027161926/https://www.fraserinstitute.org/sites/default/files/ExplodingPopulationMyths.pdf |archive-date=27 October 2021 |location=South Africa |language=en |date=October 1995 |url-status=live}}</ref> The institute also questions the sincerity of advocates of population control in poor countries.<ref name="fraserinstitute.org" /><ref> cato.org, Chelsea Follett, 24 April 2018.</ref>
The correlation does not imply cause and effect, and can be linked to the interplay of birth rates, death rates and economic development.


Nicholas Eberstadt, a ], has criticised the idea of overpopulation, saying that "overpopulation is not really overpopulation. It is a question of ]".<ref name="Nature 12-1-2015" />
Poor living conditions can also cause a very bad effect on the population; diseases such as malaria and HIV/AIDS can also contribute to this. Lack of nutrients, poor sanitation and poor health institutions. Death rate and birth rate can also have a negative effect on the population.
A 2020 study in '']'' concluded that "continued trends in female educational attainment and access to contraception will hasten declines in fertility and slow population growth", with projections suggesting world population would peak at 9.73 billion in 2064 and fall by 2100.<ref name="Lancet">{{Cite journal|last1=Vollset|first1=Stein Emil|last2=Goren|first2=Emily|last3=Yuan|first3=Chun-Wei|last4=Cao|first4=Jackie|last5=Smith|first5=Amanda E.|last6=Hsiao|first6=Thomas|last7=Bisignano|first7=Catherine|last8=Azhar|first8=Gulrez S.|last9=Castro|first9=Emma|last10=Chalek|first10=Julian|last11=Dolgert|first11=Andrew J.|date=17 October 2020|title=Fertility, mortality, migration, and population scenarios for 195 countries and territories from 2017 to 2100: a forecasting analysis for the Global Burden of Disease Study|journal=The Lancet|language=English|volume=396|issue=10258|pages=1285–1306|doi=10.1016/S0140-6736(20)30677-2|issn=0140-6736|pmid=32679112|pmc=7561721}}</ref> Media commentary interpreted this as suggesting ] represents a greater environmental threat as an overpopulation scenario may never occur.<ref name="Deutsche Welle" /><ref>{{cite web|date=10 September 2020|title=The best news of 2020? Humanity may never hit the 10 billion mark|url=https://news.mongabay.com/2020/09/the-best-news-of-2020-humanity-may-never-hit-the-10-billion-mark/|access-date=30 July 2021|website=Mongabay Environmental News|language=en-US}}</ref>


Some ] strategies advocated by proponents of overpopulation are controversial for ethical reasons. Those concerned with overpopulation, including Paul Ehrlich, have been accused of influencing human rights abuses including ] and under ], as well as mandatory or ] birth control measures taken in other countries.<ref name="Roser-2013" /><ref name="archive.is-2020" /><ref name="The Wire" /><ref>{{cite web|last=Follett|first=Chelsea|date=21 July 2020|title=Neo-Malthusianism and Coercive Population Control in China and India: Overpopulation Concerns Often Result in Coercion |url=https://www.cato.org/policy-analysis/neo-malthusianism-coercive-population-control-china-india-overpopulation-concerns|access-date=5 August 2021|website=CATO Institute}}</ref>
==Environment==
{{cquote|You know, when we first set up WWF, our objective was to save endangered species from extinction. But we have failed completely; we haven’t managed to save a single one. If only we had put all that money into condoms, we might have done some good. <small>], Founder of the ].</small><ref>{{cite web|url=http://archive.cosmosmagazine.com/opinion/a-plague-people/|title=A plague of people|work='']''|date=13 May 2010}}</ref>
}}


=== Women's rights ===
Overpopulation has substantially adversely impacted the environment of Earth starting at least as early as the 20th century.<ref name="Nielsen" /> According to the Global Footprint Network, "today humanity uses the equivalent of 1.5 planets to provide the resources we use and absorb our waste".<ref name="HO">Human overpopulation. Animal Welfare Institute. Retrieved 2014/10/25 from {{cite web|url=https://awionline.org/content/human-overpopulation |title=Archived copy |accessdate=2014-12-01 |deadurl=no |archiveurl=https://web.archive.org/web/20161022222110/http://awionline.org/content/human-overpopulation |archivedate=22 October 2016 |df=dmy }}</ref> There are also economic consequences of this ] in the form of ] attrition.<ref>Daily, Gretchen C. and Ellison, Katherine (2003) ''The New Economy of Nature: The Quest to Make Conservation Profitable'', Island Press {{ISBN|1559631546}}</ref> Beyond the scientifically verifiable harm to the environment, some assert the moral right of other species to simply exist rather than become extinct. Environmental author ] has said that "our burgeoning population and urban way of life have been purchased at the expense of vast ecosystems and habitats. ... It's no accident that as we celebrate the urbanization of the world, we are quickly approaching another historic watershed: the disappearance of the wild."<ref>{{cite news
{{See also|Feminization of poverty|Sex-selective abortion|Birth control||}}
|url=http://www.thestar.com/opinion/article/164832
|title=The risks of too much city in a crowded world
|work=Toronto Star
|date= 2006-12-24
|first=Jeremy
|last=Rifkin
}}</ref>


Influential advocates such as Betsy Hartmann consider the "myth of overpopulation" to be destructive as it "prevents constructive thinking and action on ]," which acutely affects women and communities of ].<ref name="Hartmann" /> The ] (ICPD) defines reproductive rights as "the basic right of all couples and individuals to decide freely and responsibly the number, spacing, and timing of their children and to have the information to do so."<ref>{{Cite book|last=UNFPA|title=Programme of Action: Adopted at the International Conference of Population and development, Cairo, 5–13 September 1994.|publisher=UN Population Fund|year=1994|isbn=0-89714-696-4|pages=Section 7.3}}</ref> This oversimplification of human overpopulation leads individuals to believe there are simple solutions and the creation of population policies that limit reproductive rights.{{fact|date=December 2024}}
Says Peter Raven, former President of the ] (AAAS) in their seminal work , "Where do we stand in our efforts to achieve a sustainable world? Clearly, the past half century has been a traumatic one, as the collective impact of human numbers, affluence (consumption per individual) and our choices of technology continue to exploit rapidly an increasing proportion of the world's resources at an unsustainable rate. ... During a remarkably short period of time, we have lost a quarter of the world's ] and a fifth of its agricultural land, altered the composition of the ] profoundly, and destroyed a major proportion of our forests and other natural ]s without replacing them. Worst of all, we have driven the rate of biological ], the permanent loss of species, up several hundred times beyond its historical levels, and are threatened with the loss of a majority of all species by the end of the 21st century."
], Vietnam]]


In response, philosopher Tim Meijers asks the question: "To what extent is it fair to require people to refrain from procreating as part of a strategy to make the world more sustainable?"<ref name="Meijers-2016">{{Citation |last=Meijers |first=Tim |title=Climate change and the right to one child |date=2016 |url=http://dx.doi.org/10.4324/9781315665320-14 |work=Human Rights and Sustainability |pages=181–194 |place=Abingdon, Oxon; New York : Routledge |publisher=Routledge |doi=10.4324/9781315665320-14 |isbn=9781315665320 |access-date=}}</ref> Meijers rejects the idea that the right to reproduce can be unlimited, since this would not be universalizable: "in a world in which everybody had many children, extreme scarcity would arise and stable institutions could prove unsustainable. This would lead to violation of (rather uncontroversial) rights such as the right to life and to health and subsistence."<ref name="Meijers-2016" /> In the actual world today, excessive procreation could also undermine our descendants' right to have children, since people are likely to refrain (and perhaps should refrain) from bringing children into an insecure and dangerous world. Meijers, Sarah Conly, Diana Coole, and other ethicists conclude that people have a right to found a family, but not to unlimited numbers of children.<ref name="Meijers-2016" /><ref>{{Cite book |first=Sarah |last=Conly |url=http://worldcat.org/oclc/969537327 |title=One child : do we have a right to more? |publisher=Oxford University Press |year=2016 |isbn=978-0-19-020343-6 |oclc=969537327}}</ref><ref name="Coole-2018" /><ref>Hedberg T (2021) . ''The Ecological Citizen'' '''5'''(1): 47–54.</ref>
Further, even in countries which have both large population growth and major ecological problems, it is not necessarily true that curbing the population growth will make a major contribution towards resolving all environmental problems.<ref name="UN World Population Report 2001">{{cite web|url=https://www.un.org/esa/population/publications/wpm/wpm2001.pdf|format=PDF|title=UN World Population Report 2001|page=31|accessdate=16 December 2008}}</ref> However, as developing countries with high populations become more industrialized, pollution and consumption will invariably increase.


=== Coercive population control policies ===
The ] said in 2006 that the booming economies of ] and India are "planetary powers that are shaping the global biosphere". The report states:
{{See also|Compulsory sterilization|One-child policy|Two-child policy|Three-child policy}}


Ehrlich advocated in ''The Population Bomb'' that "various forms of coercion", such as removing tax benefits for having additional children, be used in cases when voluntary population planning policies fail.<ref name="archive.is-2020-2" /> Some nations, like ], have used strict or ] measures such as the ] to reduce birth rates.<ref>{{cite news
{{quote|The world's ecological capacity is simply insufficient to satisfy the ambitions of China, India, Japan, Europe and the United States as well as the aspirations of the rest of the world in a sustainable way.<ref>"". BBC News (2006-01-12).</ref>}}
|url = http://news.independent.co.uk/world/politics/article2201090.ece
|title = Birth rates 'must be curbed to win war on global poverty'
|work = The Independent
|location = London
|date = 31 January 2007
|access-date = 20 May 2010
|url-status = dead
|archive-url = https://web.archive.org/web/20080119183753/http://news.independent.co.uk/world/politics/article2201090.ece
|archive-date = 19 January 2008}}</ref> ] or semi-compulsory sterilization, such as for token material compensation or easing of penalties,<ref>{{cite web |last1=Green |first1=Hannah Harris |title=The legacy of India's quest to sterilise millions of men |url=https://qz.com/india/1414774/the-legacy-of-indias-quest-to-sterilise-millions-of-men/ |website=Quartz |publisher=G/O Media |access-date=19 October 2022 |archive-url=https://web.archive.org/web/20221016151644/https://qz.com/india/1414774/the-legacy-of-indias-quest-to-sterilise-millions-of-men/ |archive-date=16 October 2022 |language=en |date=6 October 2018 |url-status=live}}</ref> has also been implemented in many countries as a form of population control.<ref>Vinay Lal. {{webarchive |url=https://web.archive.org/web/20160729163515/http://www.sscnet.ucla.edu/southasia/History/Independent/Indira.html |date=29 July 2016 }}, UCLA College of Letters and Science</ref><ref name="Roser-2013">{{cite web|last=Mann|first=Charles C.|title=The Book That Incited a Worldwide Fear of Overpopulation|url=https://www.smithsonianmag.com/innovation/book-incited-worldwide-fear-overpopulation-180967499/|access-date=4 August 2021|website=Smithsonian Magazine|language=en}}</ref>


Another choice-based approach is financial compensation or other benefits by the state offered to people who voluntarily undergo ]. Such policies have been introduced by the government of India.<ref>{{cite web|date=1 July 2011|title='Cars for sterilisation' campaign|url=https://www.bbc.com/news/world-south-asia-13982031|url-status=dead|archive-url=https://web.archive.org/web/20160304083235/http://www.bbc.com/news/world-south-asia-13982031|archive-date=4 March 2016|via=bbc.com}}</ref><ref name="archive.is-2020">{{cite web|date=17 May 2020|title=The forgotten roots of India's mass sterilization program – The Washi…|url=https://www.washingtonpost.com/news/morning-mix/wp/2014/11/14/the-malthusian-roots-of-indias-mass-sterilization-program/|archive-url=https://archive.today/20200517041014/https://www.washingtonpost.com/news/morning-mix/wp/2014/11/14/the-malthusian-roots-of-indias-mass-sterilization-program/|url-status=dead|archive-date=17 May 2020|access-date=4 August 2021|website=archive.is}}</ref><ref name="The Wire">{{cite web|title='Population Explosion': The Myth that Refuses to Go|url=https://thewire.in/rights/population-explosion-rakesh-sinha-bill|access-date=20 October 2021|website=The Wire}}</ref>
According to ], if China and India were to consume as much resources per capita as the United States, in 2030 they would each require a full planet Earth to meet their needs.<ref>" {{webarchive |url=https://web.archive.org/web/20160415082807/http://www.worldwatch.org/node/3893 |date=15 April 2016 }}". ]. 11 January 2006.</ref> In the long term these effects can lead to increased conflict over dwindling resources<ref>" {{webarchive |url=https://web.archive.org/web/20080608020547/http://www.globalissues.org/EnvIssues/Population/Result.asp |date=8 June 2008 }}". 26 September 2001. Retrieved 19 June 2007.</ref> and in the worst case a ].


The Indian government of ] introduced ] in 2019, including offering incentives for ] by citing the risks of a "population explosion" although demographers have criticized that basis, with India thought to be undergoing ] and its ]. The policies have also received criticism from human and women's rights groups.<ref name="The Wire" /><ref>{{Cite news|date=13 July 2021|title=Uttar Pradesh bill: The myth of India's population explosion|language=en-GB|work=BBC News|url=https://www.bbc.com/news/world-asia-india-57801764|access-date=21 October 2021}}</ref>
Many studies link population growth with ] and the effect of ].<ref>] (2004)."'' {{webarchive |url=https://web.archive.org/web/20160503035714/https://books.google.com/books?id=jE9mwoLXdwYC&pg=PA326&dq&hl=en#v=onepage&q=&f=false |date=3 May 2016 }}''". ]. p.326. {{ISBN|0-521-52874-7}}</ref><ref>{{cite news | url = http://www.independent.co.uk/environment/once-taboo-population-enters-climate-debate-1834789.html | title = Once taboo, population enters climate debate|work=The Independent |location=London | date=2009-12-05 | accessdate=21 January 2010 }}</ref>


==Warfare and conflict== === Racism ===
{{See also|Ecofascism}}
{{cquote|excessive growth may reduce output per worker, repress levels of living for the masses and engender strife. <small>] (551 – 479 BC)</small><ref>{{cite book|last1=Neurath|first1=Paul|title=From Malthus to the Club of Rome and back : problems of limits to growth, population control, and migrations|date=1994|publisher=Sharpe|location=Armonk, NY |isbn=978-1563244070|page=6}}</ref>
The concept of human overpopulation has been criticized by some scholars and environmentalists as being ] and having roots in ] and ], since control and reduction of human population is often focused on the ], instead of on ] and the ], where it occurs.<ref name="Dyett-2019" /><ref name="Thomas-2021">{{Cite journal|last1=Thomas|first1=Cassidy|last2=Gosink|first2=Elhom|date=25 March 2021|title=At the Intersection of Eco-Crises, Eco-Anxiety, and Political Turbulence: A Primer on Twenty-First Century Ecofascism|url=https://brill.com/view/journals/pgdt/20/1-2/article-p30_4.xml|journal=Perspectives on Global Development and Technology|language=en|volume=20|issue=1–2|pages=30–54|doi=10.1163/15691497-12341581|issn=1569-1500|s2cid=233663634}}</ref><ref name="Kaneda-2014" /><ref name="Alberro" /><ref>{{cite web|last=Kashwan|first=Prakash|date=13 September 2020|title=How American Environmentalism's Racist Roots Shaped Our Thoughts on Conservation|url=https://science.thewire.in/environment/us-environmentalism-racism-conservation/|access-date=30 July 2021|website=The Wire Science|language=en-GB}}</ref> ]'s ''Population Bomb'' begins with him describing first knowing the "feel of overpopulation" from a visit to ], which some critics have accused of having racial undertones.<ref>{{cite web|date=19 March 2018|title=Is the way we think about overpopulation racist? {{!}} Fred Pearce|url=http://www.theguardian.com/cities/2018/mar/19/overpopulation-cities-environment-developing-world-racist-paul-ehrlich|access-date=21 October 2021|website=The Guardian|language=en}}</ref> ] has said "when affluent white people wrongly transfer the blame for their environmental impacts on to the birthrate of much poorer brown and black people, their finger-pointing reinforces ] and ]] narratives. It is inherently racist."<ref name="Monbiot-2021">{{cite web|date=26 August 2020|title=Population panic lets rich people off the hook for the climate crisis they are causing {{!}} George Monbiot|url=http://www.theguardian.com/commentisfree/2020/aug/26/panic-overpopulation-climate-crisis-consumption-environment|access-date=30 July 2021|website=The Guardian|language=en}}</ref> Overpopulation is a common component of ] ideology.<ref name="Thomas-2021" /><ref name="www.newstatesman.com-2020" /><ref>{{Cite web |title='Eco-fascist' Arm of Neo-Nazi Terror Group, The Base, Linked to Swedish Arson |url=https://www.vice.com/en/article/qjdvzx/eco-fascist-arm-of-neo-nazi-terror-group-the-base-linked-to-swedish-arson |access-date=6 December 2022 |website=] |date=29 January 2020 |language=en}}</ref>
}}
{{cquote|Overpopulation in various countries has become a serious threat to the health of people and a grave obstacle to any attempt to organize peace on this planet. <small>] – physicist 1879 – 1955</small><ref>{{cite web|title=Quotations|url=http://www.populationmatters.org/making-case/quotations/|website=http://www.populationmatters.org/|accessdate=1 July 2014}}</ref>
}}


Scholar Heather Alberro rejects the overpopulation argument, stating that the human population growth is rapidly slowing down, the underlying problem is not the number of people, but how resources are distributed and that the idea of overpopulation could fuel a racist backlash against the population of poor countries.<ref name="Alberro">{{cite web|last=Alberro|first=Heather|title=Why we should be wary of blaming 'overpopulation' for the climate crisis|url=http://theconversation.com/why-we-should-be-wary-of-blaming-overpopulation-for-the-climate-crisis-130709|access-date=31 December 2020|website=The Conversation|date=28 January 2020 |language=en}}</ref>
It has been suggested<ref>{{cite book |last=Champion |first=Tony |editor1-first=Peter |editor1-last=Daniels |editor2-first=Michael |editor2-last=Bradshaw |editor3-first=Denis |editor3-last=Shaw |editor4-first=James |editor4-last=Sidaway |title=An Introduction to Human Geography Issues for the 21st Century Second edition|publisher=Pearson Education |year=2005 |pages=88–111 |chapter=Chapter 4: Demographic transformations |isbn=0-131-21766-6}}</ref> that overpopulation leads to increased levels of tensions both between and within countries. Modern usage of the term ] supports the idea that overpopulation may promote warfare through fear of resource scarcity and increasing numbers of youth lacking the opportunity to engage in peaceful employment (the ]).


In response, population activists argue that overpopulation is a problem in both rich and poor countries, and arguably a worse problem in rich countries, where residents’ higher per capita consumption ratchets up the impacts of their excessive numbers.<ref name="Crist-2019" /> Feminist scholar Donna Haraway notes that a commitment to enlarging the moral community to include nonhuman beings logically entails people’s willingness to limit their numbers and make room for them.<ref>{{Cite book |last=Haraway |first=Donna Jeanne |url=http://worldcat.org/oclc/1027121011 |title=Staying with the trouble : making kin in the Chthulucene |date=2016 |publisher=Duke University Press |isbn=978-0-8223-6224-1 |oclc=1027121011}}</ref> Ecological economists like Herman Daly and Joshua Farley believe that reducing populations will make it easier to achieve steady-state economies that decrease total consumption and pollution to manageable levels.<ref>{{Cite book |last1=Daly |first1=H. E. |title=Ecological economics: principles and applications |last2=Farley |first2=J |publisher=Island press |year=2011 |edition=2nd}}</ref> Finally, as Karin Kuhlemann observes, "that a population's size is stable in no way entails sustainability. It may be sustainable, or it may be far too large."<ref>Kuhlemann, K. (2018). Any size population will do?’: The fallacy of aiming for stabilization of human numbers. ''The Ecological Citizen'', ''1''(2), 181-189.</ref>
===Criticism of this hypothesis===
The ] that population pressure causes increased ] has been recently criticized on the empirical grounds. Both studies focusing on specific historical societies and analyses of cross-cultural data have failed to find positive correlation between population density and incidence of warfare. ], in collaboration with ], has shown that such negative results do not falsify the population-warfare hypothesis.<ref name=t1>Turchin P., Korotayev A. {{webarchive |url=https://web.archive.org/web/20160603173842/http://cliodynamics.ru/index.php?option=com_content&task=view&id=281&Itemid=1 |date=3 June 2016 }}. '']'' 5/2 (2006): 112–147.</ref>


According to the writer and journalist Krithika Varagur, myths and misinformation about overpopulation of ] in ] is thought to have driven their ] in the 2010s.<ref>{{cite web|last=Varagur|first=Krithika|date=14 November 2017|title=The Muslim Overpopulation Myth That Just Won't Die|url=https://www.theatlantic.com/international/archive/2017/11/muslim-overpopulation-myth/545318/|access-date=20 October 2021|website=The Atlantic|language=en}}</ref>
Population and warfare are dynamical variables, and if their interaction causes sustained oscillations, then we do not in general expect to find strong correlation between the two variables measured at the same time (that is, unlagged). Korotayev and Turchin have explored mathematically what the dynamical patterns of interaction between population and warfare (focusing on internal warfare) might be in both stateless and state societies. Next, they have tested the model predictions in several empirical case studies: early modern England, ] and ] China, and the ]. Their empirical results have supported the population-warfare theory: that there is a tendency for population numbers and internal warfare intensity to oscillate with the same period but shifted in phase (with warfare peaks following population peaks).


== Advocacy organizations ==
Furthermore, they have demonstrated that in the agrarian societies the rates of change of the two variables behave precisely as predicted by the theory: population rate of change is negatively affected by warfare intensity, while warfare rate of change is positively affected by population density.<ref name=t1/><ref>Korotayev A., Malkov A., Khaltourina D. {{webarchive |url=https://web.archive.org/web/20160802044537/http://cliodynamics.ru/index.php?option=com_content&task=view&id=172&Itemid=70 |date=2 August 2016 }}. Moscow: URSS, 2006</ref><ref>Korotayev A.V., Khaltourina D.A. {{webarchive |url=https://web.archive.org/web/20160305173249/http://urss.ru/cgi-bin/db.pl?cp=&lang=en&blang=en&list=14&page=Book&id=37485 |date=5 March 2016 }} Moscow: URSS, 2006. {{ISBN|5-484-00560-4}};</ref>
{{Main|List of population concern organizations|}}


The following organizations advocate for a limit to human population growth, although their focus may be on related issues such as environmental protection:
==Proposed solutions and mitigation measures==
{{cquote|Given the current levels of violence by this culture against both humans and the natural world, however, it's not possible to speak of reductions in population and consumption that do not involve violence and privation, not because the reductions themselves would necessarily involve violence, but because violence and privation have become the default of our culture.<small> ]. '']'', 2006</small><ref>{{cite book |last=Jensen|first=Derrick |date=2006 |title=Endgame, Vol. 1: The Problem of Civilization|url=https://books.google.com/books?id=CSsfg3325iEC&lpg=PP1&pg=PA129#v=onepage&q&f=false|location= |publisher=]|page=129 |isbn=978-1583227305|author-link=Derrick Jensen}}</ref>
}}
There are several solutions and mitigation measures that have the potential to reduce overpopulation. Some solutions are to be applied on a global planetary level (e.g., via ] resolutions), some to be applied on a local government, state, city, or other organization level, and some are to be applied on a family or an individual level. Some of the mitigations are ways to implement social norms. Overpopulation is an issue that threatens the state of the environment and therefore societies must make a change in order to reverse some of the environmental effects brought on by current social norms.


* ], a coalition of ] that calculates the annual ]<ref>{{cite web |title=Mathis Wackernagel Population Voice |url=https://www.overshootday.org/mathis-wackernagel-population/ |access-date=30 June 2022 |website=Earth Overshoot Day |language=en-US}}</ref>
For example, in societies like China, the government has put policies in place that regulate the number of children allowed to a couple. Other societies have already begun to implement social marketing strategies in order to educate the public on overpopulation effects. "The intervention can be widespread and done at a low cost. A variety of print materials (flyers, brochures, fact sheets, stickers) needs to be produced and distributed throughout the communities such as at local places of worship, sporting events, local food markets, schools and at car parks (taxis / bus stands)."<ref>{{cite news
* ]
|url=http://www.community.peacecorpsconnect.org/view/514/utilizing-social-marking-and-social-norms-to-addresss-problems-in-the-gambia |title=Utilizing social marketing and social norms to address problems in gambia |date= 2009-08-13
* ] (MAHB)
| accessdate=12 December 2010}}</ref>
* ]
* ]
* ]
* ]
* ]


Organization advocate against limits to human population growth.<ref>{{cite web | url=https://www.bloomberg.com/profile/company/0324506Z:US#xj4y7vzkg | title=Population Research Institute Inc - Company Profile and News | website=] }}</ref>
Such prompts work to introduce the problem so that social norms are easier to implement. Certain government policies are making it easier and more socially acceptable to use contraception and abortion methods. An example of a country whose laws and norms are hindering the global effort to slow population growth is Afghanistan. "The approval by Afghan President Hamid Karzai of the Shia Personal Status Law in March 2009 effectively destroyed Shia women's rights and freedoms in Afghanistan. Under this law, women have no right to deny their husbands sex unless they are ill, and can be denied food if they do."<ref>{{cite news
* ]
|url=http://www.overpopulation.org/
|title=Put women's rights back on the afghan
|publisher=Daily News Egypt |date= 2010-08-27
| accessdate=12 December 2010}}</ref>

===Education and empowerment===

One option is to focus on education about overpopulation, ], and ] methods, and to make birth-control devices like male and ] ], ] and ]s easily available. Worldwide, nearly 40% of ] (some 80 million unintended pregnancies each year).<ref>" {{webarchive |url=https://web.archive.org/web/20120523114015/https://www.google.com/hostednews/afp/article/ALeqM5gevGOq7Vctd1FmJkzO3gapTqX4ZA |date=23 May 2012 }}". ] (2009-09-21).</ref> An estimated 350 million women in the poorest countries of the world either did not want their last child, do not want another child or want to space their pregnancies, but they lack access to information, affordable means and services to determine the size and spacing of their families. In the United States, in 2001, almost half of ].<ref>{{cite journal|doi=10.1363/3809006|title=Disparities in Rates of Unintended Pregnancy In the United States, 1994 and 2001|author1=Finer, Lawrence B. |author2=Henshaw, Stanley K. |journal=Perspectives on Sexual and Reproductive Health|volume =38|issue =2|pages =90–96|year=2006|pmid=16772190}}</ref> In the ], some 514,000 women die annually of complications from pregnancy and abortion,<ref>"". United Nations Population Fund (UNFPA).</ref> with 86% of these deaths occurring in the ] region and South Asia.<ref>" {{webarchive |url=https://web.archive.org/web/20131031223858/http://www.who.int/mediacentre/news/releases/2007/pr56/en/index.html |date=31 October 2013 }}". ] (2007-10-12).</ref> Additionally, 8 million infants die, many because of ] or preventable diseases, especially from lack of access to clean drinking water.<ref>{{cite news| url=http://findarticles.com/p/articles/mi_m1571/is_46_17/ai_80774574 | work=Insight on the News | title=Q: should the United Nations support more family-planning services for poor countries? | first=Werner | last=Fornos | date=2001-12-10}}</ref>

] and their ] in particular are issues regarded to have vital importance in the debate.<ref name=popsearch>{{cite web|title=Population Matters search on "reproductive rights"|url=http://populationmatters.org/search_results.php?q=%22reproductive+rights%22|website=populationmatters.org|publisher=Population Matters}}</ref>
<blockquote>"The only ray of hope I can see – and it's not much – is that wherever women are put in control of their lives, both politically and socially; where medical facilities allow them to deal with birth control and where their husbands allow them to make those decisions, birth rate falls. Women don't want to have 12 kids of whom nine will die." {{mdash}} ]<ref>{{cite web|title=Sir David Attenborough on the roots of Climatic problems|url=http://www.independent.co.uk/news/people/profiles/sir-david-attenborough-this-awful-summer-weve-only-ourselves-to-blame-7942405.html|website=www.independent.co.uk|publisher=The Independent, UK broadsheet newspaper}}</ref></blockquote>
] announced a program to reduce its overpopulation by family planning education and putting ]. It was announced in June 2008 by the Minister of Health and Population ]. The government has set aside 480 million Egyptian pounds (about $90 million US) for the program.<ref>{{cite web|author=Independent Newspapers Online |url=http://www.iol.co.za/index.php?from=rss_Africa&set_id=1&click_id=68&art_id=nw20080611085517622C989460 |title=Population woes weigh down Egypt |publisher=IOL |date=11 June 2008 |accessdate=2011-11-30}}</ref>

Several scientists (including e.g. Paul and Anne Ehrlich) proposed that humanity should work at stabilizing its absolute numbers, as a starting point towards beginning the process of reducing the total numbers. They suggested the following solutions and policies: following a small-family-size norm worldwide (especially one-child-per-family ethos or culture), and providing contraception to all along with proper education on its use and benefits , combined with a significantly more equitable distribution of resources globally.<ref name=Ehrlich-Books/>

The business magnate ] proposed a "voluntary, non-imposed" one-child family scenario. A "]" campaign is run by ] (a UK population concern organisation), in which people are encouraged to limit themselves to small family size.

===Birth regulations===

Overpopulation issue can be mitigated by ]; some nations, like the People's Republic of China, use strict measures to reduce birth rates. Religious and ideological opposition to birth control has been cited as a factor contributing to overpopulation and poverty.<ref>{{cite news
|url=http://news.independent.co.uk/world/politics/article2201090.ece
|title=Birth rates 'must be curbed to win war on global poverty'
|work=The Independent |location=London |date= 31 January 2007
| accessdate=20 May 2010
}}</ref>

], son of late Prime Minister of India ], implemented a forced ] programme between 1975 and 1977. Officially, men with two children or more had to submit to sterilization, but there was a greater focus on sterilizing women than sterilizing men. Some unmarried young men, political opponents and ignorant men were also believed to have been sterilized {{Citation needed | reason=Claims neither supported nor mentioned by given source | date=October 2016}}. This program is still remembered and criticized in India, and is blamed for creating a public aversion to ], which hampered government programmes for decades.<ref>Vinay Lal. {{webarchive |url=https://web.archive.org/web/20160729163515/http://www.sscnet.ucla.edu/southasia/History/Independent/Indira.html |date=29 July 2016 }}, UCLA College of Letters and Science</ref>

Urban designer ] has proposed a "choice-based, marketable birth license plan" he calls "]s".<ref>{{cite web|url=http://www.corrupt.org/act/interviews/michael_e_arth/ |title=Interview: City Architect and Reconstructor Michael E. Arth by Alex Birch |publisher=Corrupt.org |date=22 May 2008 |accessdate=30 November 2011 |deadurl=yes |archiveurl=https://web.archive.org/web/20090105083809/http://www.corrupt.org/act/interviews/michael_e_arth |archivedate=5 January 2009 |df= }}</ref> Birth credits would allow any woman to have as many children as she wants, as long as she buys a license for any children beyond an average allotment that would result in ]. If that allotment was determined to be one child, for example, then the first child would be free, and the market would determine what the license fee for each additional child would cost. Extra credits would expire after a certain time, so these credits could not be hoarded by speculators. The actual cost of the credits would only be a fraction of the actual ], so the credits would serve more as a wake-up call to women who might otherwise produce children without seriously considering the long term consequences to themselves or society.<ref name="Arth, Michael E. 2010, pp. 352-362">Arth, Michael E., ''Democracy and the Common Wealth: Breaking the Stranglehold of the Special Interests'', Golden Apples Media, 2010, Chapter 35: "Overpopulation" pp. 352–362</ref>

] Another choice-based approach, similar to Arth's birth credits, is financial compensation or other benefits (free goods and/or services) by the state (or state-owned companies) offered to people who voluntarily undergo ]. Such compensation has been offered in the past by the government of India.<ref> {{webarchive |url=https://web.archive.org/web/20160304083235/http://www.bbc.com/news/world-south-asia-13982031 |date=4 March 2016 }}</ref>

In 2014 the United Nations estimated there is an 80% likelihood that the world's population will be between 9.6 billion and 12.3 billion by 2100. Most of the world's expected population increase will be in Africa and southern Asia. Africa's population is expected to rise from the current one billion to three or four billion by 2100, and Asia could add another billion in the same period.<ref>Kunzig, Robert, "A world with 11 billion people? New population projections shatter earlier estimates." National Geographic, September 18, 2014, {{cite web|url=http://news.nationalgeographic.com/news/2014/09/140918-population-global-united-nations-2100-boom-africa/ |title=Archived copy |accessdate=2015-02-25 |deadurl=no |archiveurl=https://web.archive.org/web/20161219061416/http://news.nationalgeographic.com/news/2014/09/140918-population-global-united-nations-2100-boom-africa/ |archivedate=19 December 2016 |df=dmy }}</ref> Because the median age of Africans is so low (e.g. ] = 15 years old) birth credits would have to limit fertility to one child per two women to reach the levels of developed countries immediately. For countries with a wide base in their population pyramid it will take a generation for the people who are of child bearing age to have their families.<ref name="Arth, Michael E. 2010, pp. 352-362"/> An example of ] is China, which added perhaps 400,000 more people after its one-child policy was enacted. Arth has suggested that the focus should be on the developed countries and that some combination of birth credits and additional compensation supplied by the developed countries could rapidly lead to zero population growth while also quickly raising the standard of living in developing countries.<ref name="Arth, Michael E. 2010, pp. 352-362"/>

===Extraterrestrial settlement===
{{Main article|Space colonization}}
{{See also|Space advocacy}}
Various scientists and ] authors have contemplated that overpopulation on Earth may be remedied in the future by the use of extraterrestrial settlements. In the 1970s, ] suggested building ] that could support 30,000 times the carrying capacity of Earth using just the asteroid belt, and that the ] as a whole could sustain current population growth rates for a thousand years.<ref>] (1976, 2000) ], Apogee Books {{ISBN|1-896522-67-X}}</ref> ] (1992, 1994) has projected a human population of five ] (5 x 10<sup>18</sup>)
throughout the Solar System by 3000, with the majority in the ].<ref>], (1992, 1994) ''].'' Little, Brown. {{ISBN|0-316-77163-5}}</ref> ] (1999) favours the ] as the future home of humanity, suggesting this could happen within a few centuries.<ref>], ''The Sun, The Genome, and The Internet'' (1999) Oxford University Press. {{ISBN|0-19-513922-4}}</ref> In '']'', ] suggests that the resources of the solar system could support 10 ] (10<sup>16</sup>) people. In an interview, ] claimed that overpopulation is a threat to human existence and "our only chance of long-term survival is not to remain inward looking on planet Earth but to spread out into space."<ref>The Telegraph. Stephen Hawking: mankind must move to outer space within a century. (August 2010) {{cite web|url=http://www.telegraph.co.uk/science/space/7935505/Stephen-Hawking-mankind-must-move-to-outer-space-within-a-century.html |title=Archived copy |accessdate=2014-10-25 |deadurl=no |archiveurl=https://web.archive.org/web/20141025174153/http://www.telegraph.co.uk/science/space/7935505/Stephen-Hawking-mankind-must-move-to-outer-space-within-a-century.html |archivedate=25 October 2014 |df=dmy }}</ref>

], famous inventor of the futuristic concept of ], has suggested in '']'' that colonizing space will mean breaking the ] to growth for the human species.

It may be possible for other parts of the Solar System to be inhabited by humanity at some point in the future. ] of ]'s ] in particular has pointed out that " cloud-top level, Venus is the paradise planet", as one could construct ] habitats and ] there easily, based on the concept that breathable air is a lifting gas in the dense ]. ] would, like also ], ], and ], in the upper layers of their atmospheres, even afford a ] almost exactly as strong as ] (''see'' ]).<ref>{{cite web |url=http://www.universetoday.com/15570/colonizing-venus-with-floating-cities/ |title=Colonizing Venus With Floating Cities |author=Nancy Atkinson |date=16 July 2008 |work=] |accessdate=16 July 2011}}</ref>

Many ] authors, including ], ],<ref name = clarkebipeds>''Greetings, Carbon-Based Bipeds!'' (1999) ], Voyager {{ISBN|0-00-224698-8}}</ref> and ],<ref>''The Good Earth Is Dying'' (1971) ] (published in '']'')</ref> have argued that shipping any excess population into space is not a viable solution to human overpopulation. According to Clarke, "the population battle must be fought or won here on Earth".<ref name = clarkebipeds/> The problem for these authors is not the lack of resources in space (as shown in books such as ''Mining the Sky''<ref>] (1996) ]. Addison Wesley. {{ISBN|0-201-47959-1}}</ref>), but the physical impracticality of shipping vast numbers of people into space to "solve" overpopulation on Earth. However, ]'s calculations show that Earth could offload all new population growth with a launch services industry about the same size as the current airline industry.<ref>{{cite book|author=O'Neill, Gerard K.|year=1981|title=2081: A Hopeful View of the Human Future|publisher=Simon and Schuster |isbn=0-671-44751-3}}</ref>

The ] concept, by ] (the co-inventor of ] transport) and others, envisions a capability to send up to 4 million people a decade to space per facility.<ref name=StarTram2010>{{cite web|url=http://www.startram.com/resources|title=StarTram2010: Maglev Launch: Ultra Low Cost Ultra High Volume Access to Space for Cargo and Humans|publisher=startram.com|accessdate=23 April 2011}}</ref> A&nbsp;hypothetical extraterrestrial colony could potentially grow by reproduction only (i.e., without any immigration), with all of the inhabitants being the direct descendants of the original colonists.

===Urbanization===
Despite the increase in population density within cities (and the emergence of megacities), ] states in its reports that urbanization may be the best compromise in the face of global population growth.<ref>{{cite news|url=http://news.bbc.co.uk/2/hi/in_depth/6244496.stm |title=UN Habitat calling urban living 'a good thing |publisher=BBC News |date=27 June 2007 |accessdate=2011-11-30}}</ref> Cities concentrate human activity within limited areas, limiting the breadth of environmental damage.<ref>{{cite web|url=http://www.michellenijhuis.com/ |title=National Geographic Magazine; Special report 2008: Changing Climate (Village Green-article by Michelle Nijhuis) |publisher=Michellenijhuis.com |date=29 September 2011 |accessdate=2011-11-30}}</ref> But this mitigating influence can only be achieved if ] is significantly improved<ref>{{cite web|url=http://www.unhabitat.org/content.asp?cid=2523&catid=5&typeid=6&subMenuId=0 |title=UN Habitat calling to rethink urban planning |publisher=Unhabitat.org |accessdate=2011-11-30 |deadurl=yes |archiveurl=https://web.archive.org/web/20110807191706/http://www.unhabitat.org/content.asp?cid=2523&catid=5&typeid=6&subMenuId=0 |archivedate=7 August 2011 |df= }}</ref> and city services are properly maintained.

==Graph gallery==
<gallery>
Image:Afghanistanpop.svg | ] shows a classic youth bulge.
Image:Angola population pyramid 2005.png | ] shows the same, even more pronounced.
Image:China population pyramid 2005.png| ] had an extreme youth bulge until the 1960s, when it sharply curbed partly as an effect of the ].
Image:Uspop.svg | Compare the population pyramid of the USA which was bulging until the 1960s and has steadily slimmed since.
File:LibyaPopulation2011.jpg|A population pyramid based on the 2011 Libyan population.
</gallery>


==See also== ==See also==
{{div col|colwidth=27em}}
{{wikiquote|Human overpopulation}}
* ]
{{refbegin|2}}
* ] (population growth is a factor)
* ]
* ]
* ], a rat over-population experiment
* ] * ]
* ] * ]
* ] * ]
* '']''
* ]
* ]
* ]
* ]
* ]
* ]
* ] * ]
* ]
* ]
* ] * ]
* ]
* ]
* ]
* ]
* ]
* ]
* ] * ]
* ] * ]
* ]
* ]
* ]
* ]
<br/>
;In documentary and art films
* '']''
* '']''
<br/>
;In fiction
* ]
<br/>
;Other
* ]
* ] * ]
* ] * ]
* ]
{{refend|2}}

=== Documentary and art ===
* '']''
* '']''
* '']''
*'']''
*'']''
{{Div col end}}


==References== ==References==
{{Reflist|30em}} {{reflist}}


==Further reading== ==Further reading==
{{Refbegin|colwidth=30em}}
* ], ''Democracy and the Common Wealth: Breaking the Stranglehold of the Special Interests'', (2010), Chapter 35: "Overpopulation"
* Eileen Crist and Philip Cafaro (eds). ''.'' ], 2012. {{ISBN|978-0820343853}}
*{{cite journal |last= Ehrlich|first=Paul R. |authorlink= Paul R. Ehrlich |last2= Ehrlich|first2=Anne H. |date= 9 January 2013|title=Can a collapse of global civilization be avoided? |url=http://rspb.royalsocietypublishing.org/content/280/1754/20122845 |journal=] |volume=280 |issue=1754 |pages= |doi=10.1098/rspb.2012.2845|access-date= }} <small> &nbsp; by Prof. Michael Kelly, disagreeing with the paper by Ehrlich and Ehrlich; and by the authors</small>
* ], ''Ten Billion'' (2013)
* ] (24 September 2015). , ''The Guardian''
* Fred Guter, ''The Fate of the Species: Why the Human Race May Cause Its Own Extinction and How We Can Stop It'' (2012)
* Rob Hengeveld, ''Wasted World: How Our Consumption Challenges the Planet'' (2012). <small>Focuses on the interrelationships and interactions between human overpopulation and most of the key challenges facing global society, and the pressures that overpopulation and resource consumption place on the natural environment</small>
* ], Peter Engelke, ''The Great Acceleration: An Environmental History of the Anthropocene since 1945'' (2016)
* {{cite journal |last1=Motesharrei|first1=Safa|last2=Rivas|first2=Jorge|last3=Kalnay |first3=Eugenia|date= 2014|title=Human and nature dynamics (HANDY): Modeling inequality and use of resources in the collapse or sustainability of societies|url= |journal=]|volume=101 |issue= |pages=90-102 |doi=10.1016/j.ecolecon.2014.02.014|access-date= }}
* Karen Shragg, ''Move Upstream: A Call to Solve Overpopulation.'' {{ISBN|978-0988493834}} (published November 2015). by the author, March 2017 (video, 91 minutes).
* ]. ''Countdown: Our Last, Best Hope for a Future on Earth?'' ], (2013) {{ISBN|0316097756}}
* ], . University of California, Berkeley.
* (2014), a free book of photos of the social and ecological impact of human overpopulation. ''The Population Institute,'' Washington, DC
{{Refend}}


==External links==
{{wiktionary|overpopulation}} {{wiktionary|overpopulation}}
{{Wikiquote|Human overpopulation}}
{{wikibooks|Introduction to Sociology/Demography}}
*], ]. Harvard University Press, 2010. {{ISBN|9780674034600}}

*], ''Man Swarm: How Overpopulation is Killing the Wild World''. Livetrue Books, 2015. {{ISBN|978-0986383205}}
* (April 2015), '']''
*Karen Shragg, ''Move Upstream: A Call to Solve Overpopulation.'' {{ISBN|978-0988493834}} (published November 2015). by the author, March 2017 (video, 91 minutes).
* (September 2016), ''The Guardian''
*]. ''Countdown: Our Last, Best Hope for a Future on Earth?'' ], (2013) {{ISBN|0316097756}}
* (June 2017), Bill Marsh, ''The New York Times''
* Thomas Robertson, '''' (2012), Rutgers University Press
* (July 2017), ''The Guardian.'' <small>"But the ultimate cause of all of these factors is “human overpopulation and continued population growth, and overconsumption, especially by the rich”, say the scientists."</small>
* ], Peter Engelke, ''The Great Acceleration: An Environmental History of the Anthropocene since 1945'' (2016)


{{Navboxes {{Navboxes
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{{Population}} {{Population}}
{{Population country lists}} {{Population country lists}}
{{Sustainability|state=collapsed}} {{Sustainability|state=collapsed}}
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Latest revision as of 07:28, 28 December 2024

Proposed condition wherein human numbers exceed the carrying capacity of the environment Not to be confused with Population growth.

Human overpopulation (or human population overshoot) is the idea that human populations may become too large to be sustained by their environment or resources in the long term. The topic is usually discussed in the context of world population, though it may concern individual nations, regions, and cities.

Since 1804, the global living human population has increased from 1 billion to 8 billion due to medical advancements and improved agricultural productivity. Annual world population growth peaked at 2.1% in 1968 and has since dropped to 1.1%. According to the most recent United Nations' projections, the global human population is expected to reach 9.7 billion in 2050 and would peak at around 10.4 billion people in the 2080s, before decreasing, noting that fertility rates are falling worldwide. Other models agree that the population will stabilize before or after 2100. Conversely, other researchers have found that national birth registries data from 2022 and 2023 that cover half the world's population indicate that the 2022 UN projections overestimated fertility rates by 10 to 20% and are already outdated, that the global fertility rate has possibly already fallen below the sub-replacement fertility level for the first time in human history, and that the global population will peak at approximately 9.5 billion by 2061. The 2024 UN projections report estimated that world population would peak at 10.29 billion in 2084 and decline to 10.18 billion by 2100, which was 6% lower than the UN had estimated in 2014.

Early discussions of overpopulation in English were spurred by the work of Thomas Malthus. Discussions of overpopulation follow a similar line of inquiry as Malthusianism and its Malthusian catastrophe, a hypothetical event where population exceeds agricultural capacity, causing famine or war over resources, resulting in poverty and depopulation. More recent discussion of overpopulation was popularized by Paul Ehrlich in his 1968 book The Population Bomb and subsequent writings. Ehrlich described overpopulation as a function of overconsumption, arguing that overpopulation should be defined by a population being unable to sustain itself without depleting non-renewable resources.

The belief that global population levels will become too large to sustain is a point of contentious debate. Those who believe global human overpopulation to be a valid concern, argue that increased levels of resource consumption and pollution exceed the environment's carrying capacity, leading to population overshoot. The population overshoot hypothesis is often discussed in relation to other population concerns such as population momentum, biodiversity loss, hunger and malnutrition, resource depletion, and the overall human impact on the environment.

Critics of the belief note that human population growth is decreasing and the population will likely peak, and possibly even begin to decrease, before the end of the century. They argue the concerns surrounding population growth are overstated, noting that quickly declining birth rates and technological innovation make it possible to sustain projected population sizes. Other critics claim that overpopulation concerns ignore more pressing issues, like poverty or overconsumption, are motivated by racism, or place an undue burden on the global south where most population growth happens.

Overview

Modern proponents of the concept have suggested that overpopulation, population growth and overconsumption are interdependent and collectively are the primary drivers of human-caused environmental problems such as climate change and biodiversity loss. Many scientists have expressed concern about population growth, and argue that creating sustainable societies will require decreasing the current global population. Advocates have suggested implementation of population planning strategies to reach a proposed sustainable population.

Overpopulation hypotheses are controversial, with many demographers and environmentalists disputing the core premise that the world cannot sustain the current trajectory of human population. Additionally, many economists and historians have noted that sustained shortages and famines have historically been caused by war, price controls, political instability, and repressive political regimes (often employing central planning) rather than overpopulation, and that population growth historically has led to greater technological development and advancement of scientific knowledge that has enabled the engineering of substitute goods and technology that better conserves and more efficiently uses natural resources, produces greater agricultural output with less land and less water, and addresses human impacts on the environment due to there being greater numbers of scientists, engineers, and inventors and subsequent generations of scientists overturning scientific paradigms maintained by previous generations of scientists. Instead, social scientists argue that disputes between themselves and biologists about human overpopulation are over the appropriateness of definitions being used (and often devolve into social scientists and biologists simply talking past each other).

Annual world population growth peaked at 2.1% in 1968, has since dropped to 1.1%, and could drop even further to 0.1% by 2100. Based on this, the United Nations projects the world population, which is 7.8 billion as of 2020, to level out around 2100 at 10.9 billion with other models proposing similar stabilization before or after 2100. Some experts believe that a combination of factors (including technological and social change) would allow global resources to meet this increased demand, avoiding global overpopulation. Additionally, some critics dismiss the idea of human overpopulation as a science myth connected to attempts to blame environmental issues on overpopulation, oversimplify complex social or economic systems, or place blame on developing countries and poor populations—reinscribing colonial or racist assumptions and leading to discriminatory policy. These critics often suggest overconsumption should be treated as an issue separate from population growth.

History of world population

Main article: World population milestones See also: Population growth
UN population estimates and projection 1950–2100
Map of countries and territories by fertility rate (See List of countries and territories by fertility rate.)
Human population growth rate in percent, with the variables of births, deaths, immigration, and emigration – 2018

World population has been rising continuously since the end of the Black Death, around the year 1350. The fastest doubling of the world population happened between 1950 and 1986: a doubling from 2.5 to 5 billion people in 37 years, mainly due to medical advancements and increases in agricultural productivity. Due to its impact on the human ability to grow food, the Haber process enabled the global population to increase from 1.6 billion in 1900 to 7.7 billion by November 2018 and, according to the United Nations, eight billion as of November 2022. Some researchers have analyzed this growth in population like other animal populations, human populations predictably grow and shrink according to their available food supply as per the Lotka–Volterra equations, including agronomist and insect ecologist David Pimentel, behavioral scientist Russell Hopfenberg, and anthropologist Virginia Abernethy.

World population history
Year 1806 1850 1900 1940 1950 1960 1970 1980 1990 2000 2010 2020
Billions 1.01 1.28 1.65 2.33 2.53 3.03 3.68 4.43 5.28 6.11 6.92 7.76

World population has gone through a number of periods of growth since the dawn of civilization in the Holocene period, around 10,000 BCE. The beginning of civilization roughly coincides with the receding of glacial ice following the end of the Last Glacial Period. Farming allowed for the growth of populations in many parts of the world, including Europe, the Americas and China through the 1600s, occasionally disrupted by plagues or other crises. For example, the Black Death is thought to have reduced the world's population, then at an estimated 450 million in 1350, to between 350 and 375 million by 1400.

After the start of the Industrial Revolution, during the 18th century, the rate of population growth began to increase. By the end of the century, the world's population was estimated at just under 1 billion. At the turn of the 20th century, the world's population was roughly 1.6 billion. By 1940, this figure had increased to 2.3 billion. Even more dramatic growth beginning in 1950 (above 1.8% per year) coincided with greatly increased food production as a result of the industrialization of agriculture brought about by the Green Revolution. The rate of human population growth peaked in 1964, at about 2.1% per year. Recent additions of a billion humans happened very quickly: 33 years to reach three billion in 1960, 14 years for four billion in 1974, 13 years for five billion in 1987, 12 years for six billion in 1999, 11 years for seven billion in 2010, and 12 years for 8 billion toward the end of 2022.

Map of population density by country, per square kilometer (See List of countries by population density.)

Future projections

Continent Projected 2050 population

by UN in 2017

Africa 2.5 billion
Asia 5.5 billion
Europe 716 million
Latin America and Caribbean 780 million
North America 435 million
Main article: Projections of population growth

Population projections are attempts to show how the human population might change in the future. These projections help to forecast the population's impact on this planet and humanity's future well-being. Models of population growth take trends in human development, and apply projections into the future to understand how they will affect fertility and mortality, and thus population growth.

The most recent report from the United Nations Population Division issued in 2022 (see chart) projects that global population will peak around the year 2086 at about 10.4 billion, and then start a slow decline (the median line on the chart).  As with earlier projections, this version assumes that the global average fertility rate will continue to fall, but even further from 2.5 births per woman during the 2015–2020 period to 1.8 by the year 2100.

World population prospects (2022). Note that half a child more or less per woman would cause a difference of about 8 billion people by the end of the century (blue dotted lines).

However, other estimates predict additional downward pressure on fertility (such as more education and family planning) which could result in peak population during the 2060–2070 period rather than later.

According to the UN, of the predicted growth in world population between 2020 and 2050, all of that change will come from less developed countries, and more than half will come from just 8 African countries. It is predicted that the population of sub-Saharan Africa will double by 2050. The Pew Research Center predicts that 50% of births in the year 2100 will be in Africa. As an example of uneven prospects, the UN projects that Nigeria will gain about 340 million people, about the present population of the US, to become the 3rd most populous country, and China will lose almost half of its population.

History of overpopulation hypotheses

This section needs expansion. You can help by adding to it. (March 2021)

Historical use

See also: Malthusianism

Concerns about population size or density have a long history: Tertullian, a resident of the city of Carthage in the second century CE, criticized population at the time: "Our numbers are burdensome to the world, which can hardly support us... In very deed, pestilence, and famine, and wars, and earthquakes have to be regarded as a remedy for nations, as the means of pruning the luxuriance of the human race." Despite those concerns, scholars have not found historic societies that have collapsed because of overpopulation or overconsumption.

Table of population growth in England 1780–1810 in An Essay on the Principle of Population (1826) by Thomas Malthus, which would go on to be an influential text on Malthusianism

By the early 19th century, intellectuals such as Thomas Malthus predicted that humankind would outgrow its available resources because a finite amount of land would be incapable of supporting a population with limitless potential for increase. During the 19th century, Malthus' work, particularly An Essay on the Principle of Population, was often interpreted in a way that blamed the poor alone for their condition and helping them was said to worsen conditions in the long run. This resulted, for example, in the English poor laws of 1834 and a hesitating response to the Irish Great Famine of 1845–52.

The first World Population Conference was held in 1927 in Geneva, organized by the League of Nations and Margaret Sanger.

Contemporary use

Paul R. Ehrlich's book The Population Bomb became a bestseller upon its release in 1968 and created renewed interest in overpopulation. The book predicted population growth would lead to famine, societal collapse, and other social, environmental and economic strife in the coming decades, and advocated for policies to curb it. The Club of Rome published the influential report The Limits to Growth in 1972, which used computer modeling to similarly argue that continued population growth trends would lead to global system collapse. The idea of overpopulation was also a topic of some works of English-language science fiction and dystopian fiction during the latter part of the 1960s. The United Nations held the first of three World Population Conferences in 1974. Human population and family planning policies were adopted by some nations in the late 20th century in an effort to curb population growth, including in China and India. Albert Allen Bartlett gave more than 1,742 lectures on the threat of exponential population growth starting in 1969.

American biologist Paul R. Ehrlich generated renewed interest in the topic of overpopulation with The Population Bomb (1968).

However, many predictions of overpopulation during the 20th century did not materialize. In The Population Bomb, Ehrlich stated, "In the 1970s hundreds of millions of people will starve to death in spite of any crash programs embarked upon now," with later editions changing to "in the 1980s". Despite admitting some of his earlier predictions did not come to pass, Ehrlich continues to advocate that overpopulation is a major issue.

As the profile of environmental issues facing humanity increased during the end of the 20th and the early 21st centuries, some have looked to population growth as a root cause. In the 2000s, E. O. Wilson and Ron Nielsen discussed overpopulation as a threat to the quality of human life. In 2011, Pentti Linkola argued that human overpopulation represents a threat to Earth's biosphere. A 2015 survey from Pew Research Center reports that 82% of scientists associated with the American Association for the Advancement of Science were concerned about population growth. In 2017, more than one-third of 50 Nobel prize-winning scientists surveyed by the Times Higher Education at the Lindau Nobel Laureate Meetings said that human overpopulation and environmental degradation are the two greatest threats facing mankind. In November that same year, the World Scientists' Warning to Humanity: A Second Notice, signed by 15,364 scientists from 184 countries, indicated that rapid human population growth is "a primary driver behind many ecological and even societal threats." Ehlrich and other scientists at a conference in the Vatican on contemporary species extinction linked the issue to population growth in 2017, and advocated for human population control, which attracted controversy from the Catholic church. In 2019, a warning on climate change signed by 11,000 scientists from 153 nations said that human population growth adds 80 million humans annually, and "the world population must be stabilized—and, ideally, gradually reduced—within a framework that ensures social integrity" to reduce the impact of "population growth on GHG emissions and biodiversity loss."

In 2020, a quote from David Attenborough about how humans have "overrun the planet" was shared widely online and became his most popular comment on the internet.

Key arguments

Overconsumption

See also: Planetary boundaries and Overconsumption

The World Wide Fund for Nature (WWF) and Global Footprint Network have argued that the annual biocapacity of Earth has exceeded, as measured using the ecological footprint. In 2006, WWF's Living Planet Report stated that in order for all humans to live with the current consumption patterns of Europeans, we would be spending three times more than what the planet can renew. According to these calculations, humanity as a whole was using by 2006 40% more than what Earth can regenerate. Another study by the WWF in 2014 found that it would take the equivalent of 1.5 Earths of bio-capacity to meet humanity's current levels of consumption. However, Roger Martin of Population Matters states the view: "the poor want to get rich, and I want them to get rich," with a later addition, "of course we have to change consumption habits,... but we've also got to stabilize our numbers".

Critics have questioned the simplifications and statistical methods used in calculating ecological footprints. Therefore, Global Footprint Network and its partner organizations have engaged with national governments and international agencies to test the results—reviews have been produced by France, Germany, the European Commission, Switzerland, Luxembourg, Japan and the United Arab Emirates. Some point out that a more refined method of assessing Ecological Footprint is to designate sustainable versus non-sustainable categories of consumption.

Carrying capacity

Main article: Sustainable population

Attempts have been made to estimate the world's carrying capacity for humans; the maximum population the world can host. A 2004 meta-analysis of 69 such studies from 1694 until 2001 found the average predicted maximum number of people the Earth would ever have was 7.7 billion people, with lower and upper meta-bounds at 0.65 and 98 billion people, respectively. They conclude: "recent predictions of stabilized world population levels for 2050 exceed several of our meta-estimates of a world population limit".

A 2012 United Nations report summarized 65 different estimated maximum sustainable population sizes and the most common estimate was 8 billion. Advocates of reduced population often put forward much lower numbers. Paul R. Ehrlich stated in 2018 that the optimum population is between 1.5 and 2 billion. In 2022 Ehrlich and other contributors to the "Scientists' warning on population", including Eileen Crist, William J. Ripple, William E. Rees and Christopher Wolf, stated that environmental analysts put the sustainable level of human population at between 2 and 4 billion people. Geographer Chris Tucker estimates that 3 billion is a sustainable number.

Proposed impacts

Poverty and infant and child mortality

Main articles: Demographic transition and Income and fertility

Although proponents of human overpopulation have expressed concern that growing population will lead to an increase in global poverty and infant mortality, both indicators have declined over the last 200 years of population growth.

Environmental impacts

Main article: Human impact on the environment See also: Environmental impact of agriculture

A number of scientists have argued that human impacts on the environment and accompanying increase in resource consumption threatens the world's ecosystems and the survival of human civilization. The InterAcademy Panel Statement on Population Growth, which was ratified by 58 member national academies in 1994, states that "unprecedented" population growth aggravates many environmental problems, including rising levels of atmospheric carbon dioxide, global warming, and pollution. Indeed, some analysts claim that overpopulation's most serious impact is its effect on the environment. Some scientists suggest that the overall human impact on the environment during the Great Acceleration, particularly due to human population size and growth, economic growth, overconsumption, pollution, and proliferation of technology, has pushed the planet into a new geological epoch known as the Anthropocene.

Biomass of mammals on Earth

  Livestock, mostly cattle and pigs (60%)  Humans (36%)  Wild animals (4%)

Some studies and commentary link population growth with climate change. Critics have stated that population growth alone may have less influence on climate change than other factors, such as greenhouse gas emissions per capita. The global consumption of meat is projected to rise by as much as 76% by 2050 as the global population increases, with this projected to have further environmental impacts such as biodiversity loss and increased greenhouse gas emissions. A July 2017 study published in Environmental Research Letters argued that the most significant way individuals could mitigate their own carbon footprint is to have fewer children, followed by living without a vehicle, forgoing air travel, and adopting a plant-based diet. However, even in countries that have both large population growth and major ecological problems, it is not necessarily true that curbing the population growth will make a major contribution towards resolving all environmental problems that can be solved simply with an environmentalist policy approach.

Continued population growth and overconsumption, particularly by the wealthy, have been posited as key drivers of biodiversity loss and contemporary species extinction, with some researchers and environmentalists specifically suggesting this indicates a human overpopulation scenario. The Global Assessment Report on Biodiversity and Ecosystem Services, released by IPBES in 2019, states that human population growth is a factor in biodiversity loss. IGI Global has uncovered the growth of the human population caused encroachment in wild habitats which have led to their destruction, "posing a potential threat to biodiversity components".

Some scientists and environmentalists, including Jared Diamond, E. O. Wilson, Jane Goodall and David Attenborough, contend that population growth is devastating to biodiversity. Wilson for example, has expressed concern when Homo sapiens reached a population of six billion their biomass exceeded that of any other large land dwelling animal species that had ever existed by over 100 times. Inger Andersen, the executive director of the United Nations Environment Programme, stated in December 2022 as the human population reached a milestone of 8 billion and as delegates were meeting for the 2022 United Nations Biodiversity Conference, that "we need to understand that the more people there are, the more we put the Earth under heavy pressure. As far as biodiversity is concerned, we are at war with nature."

Human overpopulation and continued population growth are also considered by some, including animal rights attorney Doris Lin and philosopher Steven Best, to be an animal rights issue, as more human activity means the destruction of animal habitats and more direct killing of animals.

Resource depletion

Main articles: Resource depletion and overconsumption

Some commentary has attributed depletion of non-renewable resources, such as land, food and water, to overpopulation and suggested it could lead to a diminished quality of human life. Ecologist David Pimentel was one such proponent, saying "with the imbalance growing between population numbers and vital life sustaining resources, humans must actively conserve cropland, freshwater, energy, and biological resources. There is a need to develop renewable energy resources. Humans everywhere must understand that rapid population growth damages the Earth's resources and diminishes human well-being."

Growth in food production has been greater than population growth.

Although food shortages have been warned as a consequence of overpopulation, according to the Food and Agriculture Organization, global food production exceeds increasing demand from global population growth. Food insecurity in some regions is attributable to the globally unequal distribution of food supplies.

The notion that space is limited has been decried by skeptics, who point out that the Earth's population of roughly 6.8 billion people could comfortably be housed an area comparable in size to the state of Texas in the United States (about 269,000 square miles or 696,706.80 square kilometres). Critics and agricultural experts suggest changes to policies relating to land use or agriculture to make them more efficient would be more likely to resolve land issues and pressures on the environment than focusing on reducing population alone.

Water scarcity, which threatens agricultural productivity, represents a global issue that some have linked to population growth. Colin Butler wrote in The Lancet in 1994 that overpopulation also has economic consequences for certain countries due to resource use.

Political systems and social conflict

It was speculated by Aldous Huxley in 1958 that democracy is threatened by overpopulation, and could give rise to totalitarian style governments. Physics professor Albert Allen Bartlett at the University of Colorado Boulder warned in 2000 that overpopulation and the development of technology are the two major causes of the diminution of democracy. However, over the last 200 years of population growth, the actual level of personal freedom has increased rather than declined. John Harte has argued population growth is a factor in numerous social issues, including unemployment, overcrowding, bad governance and decaying infrastructure. Daron Acemoglu and others suggested in a 2017 paper that since the Second World War, countries with higher population growth rates experienced the most social conflict.

Some advocates have suggested societal problems such as hunger and mass unemployment are linked to overpopulation.

According to anthropologist Jason Hickel, the global capitalist system creates pressures for population growth: "more people means more labour, cheaper labour, and more consumers." He and his colleagues have also demonstrated that capitalist elites throughout recent history have "used pro-natalist state policies to prevent women from practicing family planning" in order to grow the size of their workforce. Hickel has however argued that the cause of negative environmental impacts is resource extraction by wealthy countries. He concludes that "we should not ignore the relationship between population growth and ecology, but we must not treat these as operating in a social and political vacuum."

Epidemics and pandemics

A 2021 article in Ethics, Medicine and Public Health argued in light of the COVID-19 pandemic that epidemics and pandemics were made more likely by overpopulation, globalization, urbanization and encroachment into natural habitats.

They both play a significant role impacting human populations, including widespread illness, death, and social disruption. While they can leave a temporary loss of population, it is followed by significant loss and suffering. These events are not the sole reason for overpopulation, but lack of access to family planning and reproductive contraptions, poverty and resource depletion.

Proposed solutions and mitigation measures

Several strategies have been proposed to mitigate overpopulation.

Population planning

Main article: Human population planning

Several scientists (including Paul Ehrlich, Gretchen Daily and Tim Flannery) proposed that humanity should work at stabilizing its absolute numbers, as a starting point towards beginning the process of reducing the total numbers. They suggested several possible approaches, including:

There is good evidence from many parts of the world that when women and couples have the freedom to choose how many children to have, they tend to have smaller families.  

Some scientists, such as Corey Bradshaw and Barry Brook, suggest that, given the "inexorable demographic momentum of the global human population," sustainability can be achieved more rapidly with a short term focus on technological and social innovations, along with reducing consumption rates, while treating population planning as a long-term goal.

However, most scientists believe that achieving genuine sustainability is a long-term project, and that addressing population and consumption levels are both essential to achieving it.

In 1992, more than 1700 scientists from around the world signed onto a "World Scientists' Warning to Humanity," including a majority of the living Nobel prize-winners in the sciences. "The earth is finite," they wrote. "Its ability to absorb wastes and destructive effluent is finite. Its ability to provide food and energy is finite. Its ability to provide for growing numbers of people is finite. And we are fast approaching many of the earth's limits." The warning noted:

Pressures resulting from unrestrained population growth put demands on the natural world that can overwhelm any efforts to achieve a sustainable future. If we are to halt the destruction of our environment, we must accept limits to that growth.

Two of the five areas where the signatories requested immediate action were "stabilize population" and "ensure sexual equality, and guarantee women control over their own reproductive decisions."

In a follow-up message 25 years later, William Ripple and colleagues issued the "World Scientists' Warning to Humanity: A Second Notice." This time more than 15,000 scientists from around the world signed on. "We are jeopardizing our future by not reining in our intense but geographically and demographically uneven material consumption and by not perceiving continued rapid population growth as a primary driver behind many ecological and even societal threats," they wrote. "By failing to adequately limit population growth, reassess the role of an economy rooted in growth, reduce greenhouse gases, incentivize renewable energy, protect habitat, restore ecosystems, curb pollution, halt defaunation, and constrain invasive alien species, humanity is not taking the urgent steps needed to safeguard our imperilled biosphere." This second scientists’ warning urged attention to both excessive consumption and continued population growth. Like its predecessor, it did not specify a definite global human carrying capacity. But its call to action included "estimating a scientifically defensible, sustainable human population size for the long term while rallying nations and leaders to support that vital goal."  

Subsequent scientists' calls to action have also included calls for population planning. The 2020 "World Scientists' Warning of a Climate Emergency" stated: "Economic and population growth are among the most important drivers of increases in CO2 emissions from fossil fuel combustion." "Therefore," the study noted: "we need bold and drastic transformations regarding economic and population policies." "The world population must be stabilized—and, ideally, gradually reduced," it concluded, implying that humanity is overpopulated given current and expected levels of resource use and waste generation.

A follow-up scientists’ warning on climate change in 2021 reiterated the need to plan and limit human numbers to achieve sustainability, proposing as a goal "stabilizing and gradually reducing the population by providing voluntary family planning and supporting education and rights for all girls and young women, which has been proven to lower fertility rates."

Family planning

Main articles: Family planning, Reproductive rights, and Birth control
A family planning placard in Ethiopia. It depicts negative effects of having more children than people can care for.

Education and empowerment of women and giving access to family planning and contraception have a demonstrated impact on reducing birthrates. Many studies conclude that educating girls reduces the number of children they have. One option according to some activists is to focus on education about family planning and birth control methods, and to make birth-control devices like condoms, contraceptive pills and intrauterine devices easily available. Worldwide, nearly 40% of pregnancies are unintended (some 80 million unintended pregnancies each year). An estimated 350 million women in the poorest countries of the world either did not want their last child, do not want another child or want to space their pregnancies, but they lack access to information, affordable means and services to determine the size and spacing of their families. In the developing world, some 514,000 women die annually of complications from pregnancy and abortion, with 86% of these deaths occurring in the sub-Saharan Africa region and South Asia. Additionally, 8 million infants die, many because of malnutrition or preventable diseases, especially from lack of access to clean drinking water.

Women's rights and their reproductive rights in particular are issues regarded to have vital importance in the debate. Anthropologist Jason Hickel asserts that a nation's population growth rapidly declines - even within a single generation - when policies relating to women's health and reproductive rights, children's health (to ensure parents they will survive to adulthood), and expanding education and economic opportunities for girls and women are implemented.

A 2020 paper by William J. Ripple and other scientists argued in favor of population policies that could advance social justice (such as by abolishing child marriage, expanding family planning services and reforms that improve education for women and girls) and at the same time mitigate the impact of population growth on climate change and biodiversity loss. In a 2022 warning on population published by Science of the Total Environment, Ripple, Ehrlich and other scientists appealed to families around the world to have no more than one child and also urged policy-makers to improve education for young females and provide high-quality family-planning services.

Extraterrestrial settlement

This section is an excerpt from Space colonization § Alleviating overpopulation and resource demand.

An argument for space colonization is to mitigate proposed impacts of overpopulation of Earth, such as resource depletion. If the resources of space were opened to use and viable life-supporting habitats were built, Earth would no longer define the limitations of growth. Although many of Earth's resources are non-renewable, off-planet colonies could satisfy the majority of the planet's resource requirements. With the availability of extraterrestrial resources, demand on terrestrial ones would decline. Proponents of this idea include Stephen Hawking and Gerard K. O'Neill.

Others including cosmologist Carl Sagan and science fiction writers Arthur C. Clarke, and Isaac Asimov, have argued that shipping any excess population into space is not a viable solution to human overpopulation. According to Clarke, "the population battle must be fought or won here on Earth". The problem for these authors is not the lack of resources in space (as shown in books such as Mining the Sky), but the physical impracticality of shipping vast numbers of people into space to "solve" overpopulation on Earth.

Urbanization

Further information: New Urbanism and Sustainable urbanism

Despite the increase in population density within cities (and the emergence of megacities), UN Habitat Data Corp. states in its reports that urbanization may be the best compromise in the face of global population growth. Cities concentrate human activity within limited areas, limiting the breadth of environmental damage. UN Habitat says this is only possible if urban planning is significantly improved.

Paul R. Ehrlich proposed in The Population Bomb that rhetoric supporting the increase of city density is a means of avoiding dealing with what he views as the root problem of overpopulation and has been promoted by what he views as the same interests that have allegedly profited from population increase (such as property developers, the banking system which invests in property development, industry, and municipal councils). Subsequent authors point to growth economics as driving governments seek city growth and expansion at any cost, disregarding the impact it might have on the environment.

Criticism

See also: Population ethics and Economic consequences of population decline
Global fertility rates as of 2020. About half of the world population lives in nations with sub-replacement fertility.

The concept of human overpopulation, and its attribution as a cause of environmental issues, are controversial.

Some critics, including Nicholas Eberstadt, Fred Pearce, Dominic Lawson and Betsy Hartmann, refer to overpopulation as a myth. Predicted exponential population growth or any "population explosion" did not materialise; instead, population growth slowed. Critics suggest that enough resources are available to support projected population growth, and that human impacts on the environment are not attributable to overpopulation.

According to libertarian think tank the Fraser Institute, both the idea of overpopulation and the alleged depletion of resources are myths; most resources are now more abundant than a few decades ago, thanks to technological progress. The institute also questions the sincerity of advocates of population control in poor countries.

Nicholas Eberstadt, a political economist, has criticised the idea of overpopulation, saying that "overpopulation is not really overpopulation. It is a question of poverty".

A 2020 study in The Lancet concluded that "continued trends in female educational attainment and access to contraception will hasten declines in fertility and slow population growth", with projections suggesting world population would peak at 9.73 billion in 2064 and fall by 2100. Media commentary interpreted this as suggesting overconsumption represents a greater environmental threat as an overpopulation scenario may never occur.

Some human population planning strategies advocated by proponents of overpopulation are controversial for ethical reasons. Those concerned with overpopulation, including Paul Ehrlich, have been accused of influencing human rights abuses including forced sterilisation policies in India and under China's one-child policy, as well as mandatory or coercive birth control measures taken in other countries.

Women's rights

See also: Feminization of poverty, Sex-selective abortion, and Birth control

Influential advocates such as Betsy Hartmann consider the "myth of overpopulation" to be destructive as it "prevents constructive thinking and action on reproductive rights," which acutely affects women and communities of women in poverty. The 1994 International Conference on Population and Development (ICPD) defines reproductive rights as "the basic right of all couples and individuals to decide freely and responsibly the number, spacing, and timing of their children and to have the information to do so." This oversimplification of human overpopulation leads individuals to believe there are simple solutions and the creation of population policies that limit reproductive rights.

In response, philosopher Tim Meijers asks the question: "To what extent is it fair to require people to refrain from procreating as part of a strategy to make the world more sustainable?" Meijers rejects the idea that the right to reproduce can be unlimited, since this would not be universalizable: "in a world in which everybody had many children, extreme scarcity would arise and stable institutions could prove unsustainable. This would lead to violation of (rather uncontroversial) rights such as the right to life and to health and subsistence." In the actual world today, excessive procreation could also undermine our descendants' right to have children, since people are likely to refrain (and perhaps should refrain) from bringing children into an insecure and dangerous world. Meijers, Sarah Conly, Diana Coole, and other ethicists conclude that people have a right to found a family, but not to unlimited numbers of children.

Coercive population control policies

See also: Compulsory sterilization, One-child policy, Two-child policy, and Three-child policy

Ehrlich advocated in The Population Bomb that "various forms of coercion", such as removing tax benefits for having additional children, be used in cases when voluntary population planning policies fail. Some nations, like China, have used strict or coercive measures such as the one-child policy to reduce birth rates. Compulsory or semi-compulsory sterilization, such as for token material compensation or easing of penalties, has also been implemented in many countries as a form of population control.

Another choice-based approach is financial compensation or other benefits by the state offered to people who voluntarily undergo sterilization. Such policies have been introduced by the government of India.

The Indian government of Narendra Modi introduced population policies in 2019, including offering incentives for sterilization by citing the risks of a "population explosion" although demographers have criticized that basis, with India thought to be undergoing demographic transition and its fertility rate falling. The policies have also received criticism from human and women's rights groups.

Racism

See also: Ecofascism

The concept of human overpopulation has been criticized by some scholars and environmentalists as being racist and having roots in colonialism and white supremacy, since control and reduction of human population is often focused on the global south, instead of on overconsumption and the global north, where it occurs. Paul Ehrlich's Population Bomb begins with him describing first knowing the "feel of overpopulation" from a visit to Delhi, which some critics have accused of having racial undertones. George Monbiot has said "when affluent white people wrongly transfer the blame for their environmental impacts on to the birthrate of much poorer brown and black people, their finger-pointing reinforces narratives. It is inherently racist." Overpopulation is a common component of ecofascist ideology.

Scholar Heather Alberro rejects the overpopulation argument, stating that the human population growth is rapidly slowing down, the underlying problem is not the number of people, but how resources are distributed and that the idea of overpopulation could fuel a racist backlash against the population of poor countries.

In response, population activists argue that overpopulation is a problem in both rich and poor countries, and arguably a worse problem in rich countries, where residents’ higher per capita consumption ratchets up the impacts of their excessive numbers. Feminist scholar Donna Haraway notes that a commitment to enlarging the moral community to include nonhuman beings logically entails people’s willingness to limit their numbers and make room for them. Ecological economists like Herman Daly and Joshua Farley believe that reducing populations will make it easier to achieve steady-state economies that decrease total consumption and pollution to manageable levels. Finally, as Karin Kuhlemann observes, "that a population's size is stable in no way entails sustainability. It may be sustainable, or it may be far too large."

According to the writer and journalist Krithika Varagur, myths and misinformation about overpopulation of Rohingya people in Myanmar is thought to have driven their genocide in the 2010s.

Advocacy organizations

Main article: List of population concern organizations

The following organizations advocate for a limit to human population growth, although their focus may be on related issues such as environmental protection:

Organization advocate against limits to human population growth.

See also

Documentary and art

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