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%.[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.[2]: 14–30 Other models agree that the population will stabilize before or after 2100.[3][4][5] 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the world's population indicate that the 2022 UN projections overestimated fertility rates by 10 to 20% and are already outdated, that the global fertility rate has possibly already fallen below the sub-replacement fertility level for the first time in human history, and that the global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.[6] 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.[7][8][9]
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,[10][11] 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.[12][13] Ehrlich described overpopulation as a function of overconsumption,[14] arguing that overpopulation should be defined by a population being unable to sustain itself without depleting non-renewable resources.[15][16][17]
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.[18] The population overshoot hypothesis is often discussed in relation to other population concerns such as population momentum, biodiversity loss,[19] hunger and malnutrition,[20] resource depletion, and the overall human impact on the environment.[21]
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.[2]: 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 overconsumption, are motivated by racism, or place an undue burden on the global south where most population growth happens.[22][23]
OWOD2019 was invoked but never defined (see the help page).Roser-2013 was invoked but never defined (see the help page).Vollset-2020 was invoked but never defined (see the help page).Science was invoked but never defined (see the help page).Ceballos2017 was invoked but never defined (see the help page).When is an area overpopulated? When its population cannot be maintained without rapidly depleting nonrenewable resources [39] (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.
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