Poverty and infant and child mortality s. 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 thanks to the
agricultural and
technological revolutions.
Environmental impacts 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. of wild land mammals has declined by 85% since the emergence of humans. 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. 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, 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 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. Human overpopulation and continued population growth are also considered by some, including philosopher
Steven Best and the animal protection organization
In Defense of Animals, to be an
animal rights issue, as more human activity means the destruction of animal habitats, more direct killing of animals and more animals used as food. Recent research has expanded on the environmental consequences of overpopulation in developing regions. A 2024 study published in
Scientific Reports found that in South Asia, population density and energy consumption are significantly correlated with rising CO₂ emissions, while higher investment in human capital (education and health) helps reduce environmental degradation. The authors conclude that overpopulation and fossil fuel dependence continue to hinder progress toward sustainable development goals.
Resource depletion 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." significantly increased food production, enabling it to outpace population growth and avert widespread
famine, particularly in the latter half of the 20th century. 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. 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 ). 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. 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.
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. Scholars such as
Thomas R. Malthus,
Paul R. Ehrlich have argued that rapid
population growth can lead to societal challenges, such as worldwide
famines and mass
unemployment. For example, researcher Goran Miladinov found that in low and middle-income countries, urban and rural population growth is frequently associated with undernourishment. However, Ehrlich's predictions in
The Population Bomb have been criticised by academic journals. For example, a review by
Science (journal) outlined that his predictions of mass famine never occurred. 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." 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; other significant factors are lack of access to
family planning and reproductive contraptions,
poverty, and
resource depletion. == Proposed solutions and mitigation measures ==