Human overpopulation

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search

Graph of human population from 10000 BCE to 2000 CE. It shows exponential rise in world population that has taken place since the end of the seventeenth century.
World population

Human overpopulation (or particularly human population overshoot) refers to a human population being too large in a way that their society or environment cannot readily sustain them. It can be identified with regional human populations, but is generally discussed as an issue of world population. Overpopulation is argued to be the cause, due to demographic pressure, of overconsumption and subsequently overshoot. This leads to exceeding the carrying capacity of a geographical area and damaging the environment faster than it can be replenished. As such it is further argued that human overpopulation potentially leads to demographic push, depopulation, or even ecological or societal collapse and human extinction.

Human overpopulation was popularized by Paul Ehrlich in his book The Population Bomb. Ehrlich describes overpopulation as a function of overconsumption,[1] arguing that overpopulation should be defined by depletion of non-renewable resources. Under this definition, changes in lifestyle could cause an overpopulated area to no longer be overpopulated without any reduction in population, or vice versa.[2][3][4] Advocates suggest that contemporary human caused environmental issues (such as global warming) are signs that human world population is in a state of overpopulation, human demographics exceeding Earth's carrying capacity.[citation needed]

Discussion of overpopulation shares elements of Malthusianism and its Malthusian catastrophe, a hypothetical event where population exceeds agricultural capacity, causing famine or war over resources, resulting in poverty and depopulation. Critics of overpopulation as an approach to policy or scholarship highlight how attempts to blame environmental issues on overpopulation tend to oversimplify, placing blame on developing countries and poor populations rather than developed countries who are responsible for environmental issues like climate change—reinscribing colonial or racist assumptions. Other critics highlight that proponents rely too much on assumptions of resource scarcity and ignoring other processes such as technological innovation.

History of concept[edit]

Concern about overpopulation is an ancient topic. Tertullian was a resident of the city of Carthage in the second century CE, 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, Plato, Aristotle and others broached the topic as well.[5] While the issue has occupied past people, scholars have not found historic societies which have collapsed because of overpopulation or overconsumption.[6]

By the beginning of the 19th century, the world population had grown to a billion individuals, and 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.[7] Mercantilists argued that a large population was a form of wealth, which made it possible to create bigger markets and armies. The rich have always known that the real value of their fortune is "how much labor will it purchase?" This because almost all things humans value are only frozen labor. So the more numerous and poorer the population, the less those workers can charge for their labor.[citation needed]

During the 19th century, Malthus' 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.[8] This resulted, for example, in the English poor laws of 1834[8] and a hesitating response to the Irish Great Famine of 1845–52.[9]

A 2014 study published in Science asserts that population growth will continue into the next century.[10][11] Adrian Raftery, a University of Washington 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."[12] UN projections from 2011 suggest the population could grow to as many as 15 billion by 2100.[13]

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 humankind.[14] In November that same year, a statement by 15,364 scientists from 184 countries indicated that rapid human population growth is the "primary driver behind many ecological and even societal threats."[15]

In spite of concerns about overpopulation, widespread in developed countries, the number of people living in extreme poverty globally shows a stable decline (this has been disputed by some experts[16][17][18]), even though the population has grown seven-fold over the last 200 years. Child mortality has declined, which in turn has led to reduced birth rates, thus slowing overall population growth.[19] The global number of famine-related deaths have declined, and food supply per person has increased with population growth.[20]

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."[21][22]

Global population dynamics, their history and factors[edit]

Areas of high population densities, calculated in 1994
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.[23] The fastest doubling of the world population happened between 1950 and 1986: a doubling from 2.5 to 5 billion people in just 37 years,[24] mainly due to medical advancements and increases in agricultural productivity.[25][26]

Due to its dramatic impact on the human ability to grow food, the Haber process served as the "detonator of the population explosion," enabling the global population to increase from 1.6 billion in 1900 to 7.7 billion by November 2018.[27]

The rate of population growth has been declining since the 1980s, while the absolute total numbers are still increasing. Recent rate increases in several countries[where?] previously enjoying steady declines have apparently been contributing to continued growth in total numbers.[citation needed] The United Nations has expressed concerns on continued population growth in sub-Saharan Africa.[28] Recent research has demonstrated that those concerns are well grounded.[29][30][31]

History of world population[edit]

Year Billion
1804 1
1927 2
1959 3
1974 4
1987 5
1999 6
2011 7
2021 7.8[32]

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.[33]

It is estimated that between 1–5 million people, subsisting on hunting and foraging, inhabited the Earth in the period before the Neolithic Revolution, when human activity shifted away from hunter-gathering and towards very primitive farming.[34]

Farming allowed growth of populations in many parts of the world, include Europe, the Americas and China through the 1600s, occasionally disrupted by plagues or other crisis.[35] [36] For example, 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.[37] The population of Europe stood at over 70 million in 1340;[38] these levels did not return until 200 years later.[39] In other parts of the globe, China's population census at the founding of the Ming dynasty in 1368 indicated that the population stood close to 60 million, (though these figures are debated by some historians) approaching 150 million by the end of the dynasty in 1644.[40][41] The population of the Americas in 1500 may have been between 50 and 100 million.[42] Encounters between European explorers and other populations introduced local epidemics or other violence: for example, 90% of the Native American population of the New World through Old World diseases such as smallpox, measles, and influenza,[43] or the slave trade in Africa greatly damaged populations.[44]

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.[45] At the turn of the 20th century, the world's population was roughly 1.6 billion.[45] 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.[46] The rate of human population growth peaked in 1964, at about 2.1% per year.[47] By 1940, this figure had increased to 2.3 billion.[48] Each subsequent addition of a billion humans took less and less time: 33 years to reach three billion in 1960, 14 years for four billion in 1974, 13 years for five billion in 1987, and 12 years for six billion in 1999.[49]


External video
video icon How Earth's Population Exploded: Bloomberg Quicktake

From a historical perspective, technological revolutions have coincided with population expansion. There have been three major technological revolutions—the tool-making revolution, the agricultural revolution, and the industrial revolution—all of which allowed humans more access to food; hence increasing the carrying capacity, resulting in subsequent population explosions.[50][51] For example, the use of tools, such as bow and arrow, allowed primitive hunters greater access to more 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 industrial revolution as machinery, fertilizers, herbicides, and pesticides were used to increase land under cultivation as well as crop yields. Today, starvation is caused by economic and political forces rather than a lack of the means to produce food.[52][53]

Significant increases in human population occur whenever the birth rate exceeds the death rate 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, resulting in significant population growth. For example, until the 1700s, seven out of ten children died before reaching reproductive age.[54]

Agriculture has sustained human population growth and has been the main driving factor behind it. With more food supply, the population grows with it. This occurs most in regions which are fertile and capable of higher food production in contrast to infertile regions unable to support agricultural productivity on larger or any scales at all. 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.[55][56][57][58]

Humans have historically exploited the environment using the easiest, most accessible resources first. The richest farmland was plowed and the richest mineral ore mined first. Anne Ehrlich, Gerardo Ceballos, and Paul Ehrlich note that overpopulation is demanding the use of ever more creative, expensive and/or environmentally destructive means in order to exploit ever more difficult to access and/or poorer quality natural resources to satisfy consumers.[59]

Population as a function of food availability[edit]

Central Australian landscape. Australia is mostly unpopulated as a result of having amongst the least fertile soils in the world.[60][61]

Many people from a wide range of academic fields and political backgrounds—including agronomist and insect ecologist David Pimentel,[62] behavioral scientist Russell Hopfenberg,[63] anthropologist Virginia Abernethy,[64] ecologist Garrett Hardin,[65] science writer and anthropologist Peter Farb, journalist Richard Manning,[66]cultural critic and writer Daniel Quinn,[67] and anarcho-primitivist John Zerzan,[68]—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.

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 hunter-gatherers fluctuate in accordance with the amount of available food. The world human population began increasing after the Neolithic Revolution and its increased food supply.[69] This was, subsequent to the Green Revolution, followed by even more severely accelerated population growth, which continues today.

Critics of this theory point out that, in the modern era, birth rates are lowest in the developed nations, 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.[70] 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.[62]

Regardless of criticisms against the theory that population is a function of food availability, the human population is, on the global scale, undeniably increasing,[71] 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 a whole, since the world has become a globalized system with food moving across national borders from areas of abundance to areas of scarcity. Hopfenberg and Pimentel's findings support both this[62] and Quinn's direct accusation that "First World farmers are fueling the Third World population explosion."[72]

Current population dynamics[edit]

As of February 25, 2021, the world's human population is estimated to be 7.854 billion.[73] Or, 7,622,106,064 on 14 May 2018 and the United States Census Bureau calculates 7,472,985,269 for that same date[74] and over 7 billion by the United Nations.[75][76][77] The population is expected to reach between 8 and 10.5 billion between the years 2040[78][79] and 2050.[80] In 2017, the United Nations increased the medium variant projections[81] to 9.8 billion for 2050 and 11.2 billion for 2100.[82] The UN population forecast of 2017 was predicting "near end of high fertility" globally and anticipating that by 2030 over ⅔ of the world population will be living in countries with fertility below the replacement level[83] and for total world population to stabilize between 10 and 12 billion people by the year 2100.[84]

The rapid increase in world population over the past three centuries has raised concerns among some people that the planet may not be able to sustain the future or even present number of its inhabitants. The InterAcademy Panel Statement on Population Growth, circa 1994, stated that many environmental problems, such as rising levels of atmospheric carbon dioxide, global warming, and pollution, are aggravated by the population expansion.[85]

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

Dangers and effects[edit]

Biologists and sociologists have discussed overpopulation as a serious threat to the quality of human life.[86][87] Some deep ecologists, such as the radical thinker and polemicist Pentti Linkola, see human overpopulation as a threat to the entire biosphere.[88]

The effects of overpopulation are compounded by overconsumption. 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.[citation needed] According to Paul R. Ehrlich:

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 life support systems.[89]

However, Ehrlich's earlier predictions were controversial. In 1968 he wrote a book The Population Bomb, in which he famously stated that "[i]n the 1970s hundreds of millions of people will starve to death in spite of any crash programs embarked upon now."[90]

Some economists, such as Thomas Sowell[91] and Walter E. Williams[92] argue that third world poverty and famine are caused in part by bad government and bad economic policies.

David Attenborough described the level of human population on the planet as a multiplier of all other environmental problems.[93] In 2013, he described humanity as "a plague on the Earth" that needs to be controlled by limiting population growth.[94]

Poverty, and infant and child mortality[edit]

The UN Human Development Report 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 standard of living have been deeper and more long-lasting than what was seen in the industrialised countries during the depression in the 1930s. 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".

Youth unemployment is also soaring, with the economy unable to absorb the spiraling numbers of those seeking to enter the work force. Many young people do not have the skills to match the needs of the Egyptian market, and the economy is small, weak and insufficiently industrialized... Instead of being something productive, the population growth is a barrel of explosives.

— — Ofir Winter, an Egypt specialist at the Institute for National Security Studies[95]
As the world's population has grown, the percentage of the world's population living on less than $1 per day (adjusted for inflation) has halved in 20 years. The graph shows the 1981–2001 period.

The United Nations indicates that about 850 million people are malnourished or starving,[96] and 1.1 billion people do not have access to safe drinking water.[97] 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.[98]

Log-log graph of total fertility rate (TFR) vs. GDP (PPP) per capita with population size shown as bubble area, for all countries having population greater than 2 million (2016 estimates; 30 largest countries bold).[99][100][101]

High rates of infant mortality are associated with poverty. Rich countries with high population densities have low rates of infant mortality.[102][103] However, both global poverty and infant mortality has declined over the last 200 years of population growth.[19][20]

Environmental impacts[edit]

An industrial area, with a power plant, south of Yangzhou's downtown, China

Overpopulation has substantially adversely impacted the environment of Earth starting at least as early as the 20th century.[87] 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".[104] There are also economic consequences of this environmental degradation in the form of ecosystem services attrition.[105] 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 Jeremy Rifkin 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."[106] 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.[107][108]

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.[109]

The Worldwatch Institute said in 2006 that the booming economies of China and India are "planetary powers that are shaping the global biosphere". The report states:

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.[110]

According to Worldwatch Institute, 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.[111] In the long term these effects can lead to increased conflict over dwindling resources.[112]

Many studies link population growth with emissions and the effect of climate change.[113][114] The global consumption of meat is projected to rise by as much as 76% by 2050 as the global population surges to more than 9 billion, resulting in further biodiversity loss and increased GHG emissions.[115][116]

Biodiversity loss and the Holocene extinction[edit]

Chris Hedges, 2009[117]

Human overpopulation, continued population growth, and overconsumption are the primary drivers of biodiversity loss and the 6th (and ongoing) mass species extinction.[118][119][120][121][122] Present extinction rates may be as high as 140,000 species lost per year due to human activity, such as slash-and-burn techniques that sometimes are practiced by shifting cultivators, especially in countries with rapidly expanding rural populations, which have reduced habitat in tropical forests.[123]

Sir David King, former chief scientific adviser to the UK government, told a parliamentary inquiry: "It is self-evident that the massive growth in the human population through the 20th century has had more impact on biodiversity than any other single factor."[124][125] Paul and Anne Ehrlich said population growth is one of the main drivers of the Earth's extinction crisis.[126]

The Global Assessment Report on Biodiversity and Ecosystem Services, released by IPBES in 2019, says that human population growth is a significant factor in biodiversity loss.[127] The report asserts that expanding human land use for agriculture and overfishing are the main causes of this decline.[128] The 2020 World Wildlife Fund's Living Planet Report posits that 68% of vertebrate wildlife has been lost since 1970 due to human actions, including overconsumption, population growth, global trade and intensive farming.[129][130]


Population growth increases levels of air pollution, water pollution, soil contamination and noise pollution.[131]

Air pollution is causing changes in atmospheric composition and consequent global warming[132][133][134] and ocean acidification.[135]

Potential ecological collapse[edit]

Ecological collapse refers to a situation where an ecosystem suffers a drastic, possibly permanent, reduction in carrying capacity for all organisms, often resulting in mass extinction. Usually, an ecological collapse is precipitated by a disastrous event occurring on a short time scale. Ecological collapse can be considered as a consequence of ecosystem collapse on the biotic elements that depended on the original ecosystem.[136][137]

The ocean is in great danger of collapse. In a study of 154 different marine fish species, David Byler came to the conclusion that many factors such as overfishing, climate change, and fast growth of fish populations will cause ecosystem collapse.[138] When humans fish, they usually will fish the populations of the higher trophic levels such as salmon and tuna. The depletion of these trophic levels allow the lower trophic level to overpopulate, or populate very rapidly. For example, when the population of catfish is depleting due to overfishing, plankton will then overpopulate because their natural predator is being killed off. This causes an issue called eutrophication. Since the population all consumes oxygen the dissolved oxygen (DO) levels will plummet. The DO levels dropping will cause all the species in that area to have to leave, or they will suffocate. This along with climate change, and ocean acidification can cause the collapse of an ecosystem.

Depletion and destruction of resources[edit]

The resources to be considered when evaluating whether an ecological niche is overpopulated include clean water, 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 sewage treatment, waste disposal and energy supplies. Overpopulation places competitive stress on the basic life sustaining resources,[139] leading to a diminished quality of life.[87]

David Pimentel 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."[140][141]

These reflect the comments also of the United States Geological Survey in their paper "The Future of Planet Earth: Scientific Challenges in the Coming Century": "As the global population continues to grow...people will place greater and greater demands on the resources of our planet, including mineral and energy resources, open space, water, and plant and animal resources." "Earth's natural wealth: an audit" by New Scientist 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.[142] 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.[142] 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".[143]

On the other hand, some cornucopian researchers, such as Julian L. Simon and Bjørn Lomborg 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 The Independent.[144] 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...[however] 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 deforestation, loss of species, soil erosion, and pollution from pesticides and fertilizer runoff as farming intensifies and new land is brought into production."[145]

According to the Millennium Ecosystem Assessment, 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."[146] "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."[147][148]

Another study was done by the United Nations Environment Programme (UNEP) called the Global Environment Outlook.[149]

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.[150]

Fresh water[edit]

Overpopulation may lead to inadequate fresh water[97] for drinking as well as sewage treatment and effluent discharge.[citation needed]Some countries, like Saudi Arabia, use energy-expensive desalination to solve the problem of water shortages.[151][152]

Fresh water supplies, on which agriculture depends, are running low worldwide.[153][154] This water crisis is only expected to worsen as the population increases.[155] 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.[156] The water tables are falling in scores of countries (including Northern China, the US, and India) owing to widespread overdrafting beyond sustainable yields. Other countries affected include Pakistan, Iran, and Mexico. This overdrafting is already leading to water scarcity and cutbacks in grain harvest. Even with the overpumping of its aquifers, 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 water shortages. Desalination is also considered a viable and effective solution to the problem of water shortages.[151][157]

Overpopulation together with water deficits could trigger regional tensions, including warfare.[158]


Percentages of the Earth's surface covered by water, dedicated to agriculture, under conversion, intact, and used for human habitation. While humans occupy only 0.05% of the Earth's total area, human effects are felt on over one-quarter of the land.

The World Resources Institute states that "Agricultural conversion to croplands and managed pastures has affected some 3.3 billion [hectares]—roughly 26 percent of the land area. All totaled, agriculture has displaced one-third of temperate and tropical forests and one-quarter of natural grasslands."[159][160] Forty percent of the land area is under conversion and fragmented; less than one quarter, primarily in the Arctic and the deserts, remains intact.[161] Usable land may become less useful through salinization, deforestation, desertification, erosion, and urban sprawl. The development of energy sources may also require large areas, for example, the building of hydroelectric dams. 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.[162]

Some countries, such as the United Arab Emirates and particularly the Emirate of Dubai have constructed large artificial islands, or have created large dam and dike systems, like the Netherlands, which reclaim land from the sea to increase their total land area.[163][164] Some scientists have said that in the future, densely populated cities will use vertical farming to grow food inside skyscrapers.[165] 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).[166]


Some scientists argue that there is enough food to support the world population,[167][168] and some dispute this, particularly if sustainability is taken into account.[169] 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.[170] However, the observed figures for 2016 show an actual increase in absolute numbers of undernourished people in the world, 815 million in 2016 versus 777 million in 2015.[171] The FAO estimates that these numbers are still far lower than the nearly 900 million registered in 2000.[171]

Growth in food production has been greater than population growth.

The amounts of natural resources in this context are not necessarily fixed, and their distribution is not necessarily a zero-sum game. For example, due to the Green Revolution 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. As world population doubled from 3 to 6 billion, daily calorie 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.[172] However, others question these statistics.[173]

Percentage of population suffering from undernourishment by country, according to United Nations statistics.

The Food and Agriculture Organization of the United Nations states in its report The State of Food Insecurity in the World 2018 that the new data indicates an increase of hunger in the world, reversing the recent trend. It is estimated that in 2017 the number of undernourished people increased to 821 million, around 11 per cent of the world population. The FAO states: "Evidence shows that, for many countries, recent increases in hunger are associated with extreme climate events, especially where there is both high exposure to climate extremes and high vulnerability related to agriculture and livelihood systems."[171]

Although the proportion of "starving" people in sub-Saharan Africa 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.[173] 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.[147][174]

Food security will become more difficult to achieve as resources run out. Resources in danger of becoming depleted include oil, phosphorus, grain, fish, and water.[175][176] The British scientist John Beddington predicted in 2009 that supplies of energy, food, and water will need to be increased by 50% to reach demand levels of 2030.[177][178] According to the Food and Agriculture Organization (FAO), food supplies will need to be increased by 70% by 2050 to meet projected demands.[179]

Warfare and conflict over dwindling resources[edit]

Overpopulation causes crowding, and conflict over scarce resources, which in turn lead to increased levels of warfare.[180]

It has been suggested[181] that overpopulation leads to increased levels of tensions both between and within countries. Modern usage of the term "lebensraum" 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 youth bulge theory).[citation needed]

Criticism of this hypothesis[edit]

The hypothesis that population pressure causes increased warfare has been recently criticized on statistical grounds. Two 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. Andrey Korotayev, in collaboration with Peter Turchin, has shown that such negative results do not falsify the population-warfare hypothesis.[182]

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.[182][183][184]

Relation to non-human population growth[edit]

Biomass of mammals on Earth[185][186]

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

Human population, its prevailing growth of demands of livestock and other domestic animals, has added overshoot through domestic animal breeding, keeping and consumption, especially with the environmentally destructive industrial livestock production.[187]


  • Loss of arable land and increase in desertification.[188] Deforestation and desertification can be reversed by adopting property rights, and this policy is successful even while the human population continues to grow.[189]
  • Increased chance of the emergence of new epidemics and pandemics.[190] For many environmental and social reasons, including overcrowded living conditions, malnutrition and inadequate, inaccessible, or non-existent health care, the poor are more likely to be exposed to infectious diseases.[191]
  • Starvation, malnutrition[96] or poor diet with ill health and diet-deficiency diseases (e.g. rickets). However, rich countries with high population densities do not have famine.[92]
  • Low life expectancy in countries with fastest growing populations.[192] Overall life expectancy has increased globally despite of population growth, including countries with fast-growing populations.[19]
  • Unhygienic living conditions for many based upon water resource depletion, discharge of raw sewage[193] and solid waste disposal. However, this problem can be reduced with the adoption of sewers. For example, after Karachi, Pakistan installed sewers, its infant mortality rate fell substantially.[194]
  • Elevated crime rate due to drug cartels and increased theft by people stealing resources to survive.[195]
  • Less personal freedom and more restrictive laws. Laws regulate and shape politics, economics, history and society and serve as a mediator of relations and interactions between people. 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 and relations. It was speculated by Aldous Huxley in 1958 that democracy is threatened by overpopulation, and could give rise to totalitarian style governments.[196] However, over the last 200 years of population growth, the actual level of personal freedom has increased rather than declined.[19]

Future dynamics[edit]

Projections of population growth[edit]

Continent Projected 2050 population[197]
Africa 2.5 billion
Asia 5.5 billion
Europe 716 million
Latin America and Caribbean 780 million
North America 435 million

According to projections, the world population will continue to grow until at least 2050, with the population reaching 9 billion in 2040,[198][199] and some predictions putting the population as high as 11 billion in 2050.[200] The median estimate for future growth sees the world population reaching 8.6 billion in 2030, 9.8 billion in 2050 and 11.2 billion by 2100[201] assuming a continuing decrease in average fertility rate from 2.5 births per woman in 2010–2015 to 2.2 in 2045–2050 and to 2.0 in 2095–2100, according to the medium-variant projection.[201] Walter Greiling 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 Third World and a sanitation of the tropics.[202]

Demographic transition[edit]

Babies per woman (total fertility) in USA, Russia, China, Nigeria; 1800-2018

The theory of demographic transition held that, after the standard of living and life expectancy increase, family sizes and birth rates decline. Some research has suggested that fertility tends to increase again at very high levels of development, producing a "J"-shaped relationship between development and fertility,[203] but those increases have not been shown to be sustained.[204]

Many countries have high population growth rates but lower total fertility rates 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. "Demographic entrapment" is a concept developed by Maurice King, Honorary Research Fellow at the University of Leeds, 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.[205]

For the world as a whole, the number of children born per woman decreased from 5.02 to 2.65 between 1950 and 2005. A breakdown by region is as follows:

  • Europe – 2.66 to 1.41
  • 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

Excluding the theoretical 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.[206]

Maximum sustainable human consumption[edit]

Some groups (for example, the World Wide Fund for Nature[207][208] and Global Footprint Network) have stated that the yearly biocapacity of Earth is being 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.[209] Humanity as a whole was using, by 2006, 40 percent more than what Earth can regenerate.[210] 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 stabilise our numbers".[211] 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.[212]

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.[213] Some point out that a more refined method of assessing Ecological Footprint is to designate sustainable versus non-sustainable categories of consumption.[214][215]

Carrying capacity[edit]

Many studies have tried to estimate the world's carrying capacity for humans, that is, the maximum population the world can host.[216] A 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".[217]

Advocates of reduced population, often put forward much lower numbers. For example, Paul R. Ehrlich stated in 2018 that the optimum size of the global human population is between 1.5 and 2 billion.[218] Geographer Chris Tucker estimates that 3 billion is a sustainable number.[219]

Critics of overpopulation criticize the basic assumptions associated with these estimates. For example, Jade Sasser believes that calculating a maximum of number of humanity which may be allowed to live while only some, mostly privileged European former colonial powers, are mostly responsible for unsustainably using up the Earth is wrong.[220]

Urban growth[edit]

Urban areas with at least one million inhabitants in 2006. 3% of the world's population lived in cities in 1800, rising to 47% at the end of the twentieth century.

In 1800 only 3% of the world's population 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".[221] If the trend continues, the world's urban population will double every 38 years. In 2007 UN forecasted that urban population would rise to three out of five or 60% by 2030 and an increase in urban population from 3.2 billion to nearly 5 billion by 2030.[222] As of 2018 55% live in cities and UN predicts that it will be 68% by 2050.[223]

% of world population living in cities
Year 1800 2000 2018 2050
% City 3% 47% 55% *68%

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 developing countries.[224] One billion people, one-seventh of the world's population, or one-third of urban population, now live in shanty towns,[225] which are seen as sources of social problems such as unemployment, poverty, crime, drug addiction, alcoholism, and other social ills. In many poor countries, slums exhibit high rates of disease due to unsanitary conditions, malnutrition, and lack of basic health care.[226]

Proposed solutions and mitigation measures[edit]

Several solutions and mitigation measures have the potential to reduce overpopulation. Some solutions are to be applied on a global planetary level (e.g., via UN resolutions), while some on a country or state government organization level, and some on a family or an individual level. Some of the proposed mitigations aim to help implement new social, cultural, behavioral and political norms to replace or significantly modify current norms. For example, in countries like China, the government has put policies in place that regulate the number of children allowed to a couple. Other countries have implemented social marketing strategies in order to educate the public on overpopulation effects. Such prompts work to introduce the problem so that new or modified social norms are easier to implement. Education and empowerment of women and giving access to family planning and contraception have demonstrated positive impacts on reducing birthrates.

Scientists and technologists including e.g. Huesemann and Ehrlich caution that science and technology, as currently practiced, cannot solve the serious problems global human society faces, and that a cultural-social-political shift is needed to reorient science and technology in a more socially responsible and environmentally sustainable direction.[227][228]

Reducing overpopulation[edit]

Education and empowerment[edit]

A family planning placard in Ethiopia. It shows some negative effects of having more children than people can care for.

One option according to some activists is to focus on education about overpopulation, family planning, and birth control methods, and to make birth-control devices like male and female condoms, contraceptive pills and intrauterine devices easily available. Worldwide, nearly 40% of pregnancies are unintended (some 80 million unintended pregnancies each year).[229] 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 pregnancies were unintended.[230] In the developing world, some 514,000 women die annually of complications from pregnancy and abortion,[231] with 86% of these deaths occurring in the sub-Saharan Africa region and South Asia.[232] Additionally, 8 million infants die, many because of malnutrition or preventable diseases, especially from lack of access to clean drinking water.[233]

Women's rights and their reproductive rights in particular are issues regarded to have vital importance in the debate.[234] This incentive, however, has been questioned by Rosalind Pollack Petchesky. Citing his attendance of the 1994 Cairo conference, he reported that overpopulation and birth control were being diverted by feminists into women's rights issues, mostly downplaying the overpopulation issue as only one minor matter of many others; most of these focusing on women's rights. Upon his observation, he argued this was forging many faults and distractions on the main problem of human overpopulation and how to solve it.[235]

Several scientists (including e.g. Paul and Anne Ehrlich and Gretchen Daily) 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 socio-cultural-behavioral norm worldwide (especially one-child-per-family ethos), and providing contraception to all along with proper education on its use and benefits (while providing access to safe, legal abortion as a backup to contraception), combined with a significantly more equitable distribution of resources globally.[236][237] In the book "Evolution Science and Ethics in the Third Millennium", Robert Cliquet and Dragana Avramov also point out that the one (and a half)-child-per-family ethos is certainly a good one and that we should reduce the world population so that it is no larger than 1 to 3 billion.[238]

Population planning that is intended to reduce population size or growth rate may promote or enforce one or more of the following practices, although there are other methods as well:

  • Greater and better access to contraception
  • Reducing infant mortality so that parents do not need to have many children to ensure at least some survive to adulthood.[239]
  • Improving the status of women in order to facilitate a departure from traditional sexual division of labour.
  • One-Child and Two-Child policies, and other policies restricting or discouraging births directly.
  • Family planning[240]
  • Creating small family "role models"[240]
  • Tighter immigration restrictions

Birth regulations[edit]

Comparing Population Growth By Country's Development, 2002.svg

Overpopulation can be mitigated by birth control; 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.[241]

Sanjay Gandhi, son of late Prime Minister of India Indira Gandhi, implemented a forced sterilization 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 and political opponents may also have been sterilized.[citation needed] This program is still remembered and criticized in India, and is blamed for creating a public aversion to family planning, which hampered government programs for decades.[242]

Another choice-based approach is financial compensation or other benefits (free goods and/or services) by the state (or state-owned companies) offered to people who voluntarily undergo sterilization. Such compensation has been offered in the past by the government of India.[243]

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 four billion by 2100, and Asia could add another billion in the same period.[244]

Extraterrestrial settlement[edit]

Various scientists and science fiction authors have contemplated that overpopulation on Earth may be remedied in the future by the use of extraterrestrial settlements. In the 1970s, Gerard K. O'Neill suggested building space habitats that could support 30,000 times the carrying capacity of Earth using just the asteroid belt, and that the Solar System as a whole could sustain current population growth rates for a thousand years.[245] Marshall Savage (1992, 1994) has projected a human population of five quintillion (5 × 1018) throughout the Solar System by 3000, with the majority in the asteroid belt.[246] In Mining the Sky, John S. Lewis suggests that the resources of the solar system could support 10 quadrillion (1016) people. In an interview, Stephen Hawking 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."[247] K. Eric Drexler has suggested in Engines of Creation that settling space will mean breaking the Malthusian limits to growth for the human species.[citation needed]

Many science fiction authors, including Carl Sagan, Arthur C. Clarke,[248] and Isaac Asimov,[249] 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".[248] The problem for these authors is not the lack of resources in space (as shown in books such as Mining the Sky[250]), but the physical impracticality of shipping vast numbers of people into space to "solve" overpopulation on Earth. However according to calculations by Gerard K. O'Neill all new population growth could be facilitated with a launch services industry about the same size as the current airline industry.[251]


Despite the increase in population density within cities (and the emergence of megacities), UN Habitat states in its reports that urbanization may be the best compromise in the face of global population growth.[252] Cities concentrate human activity within limited areas, limiting the breadth of environmental damage.[253] But this mitigating influence can only be achieved if urban planning is significantly improved[254] and city services are properly maintained.

Paul Ehrlich pointed out in his book The Population Bomb (1968) argues that rhetoric supporting the increase of city density as a means of avoiding dealing with the actual problem of overpopulation to begin with and rather than treating the increase of city density as a symptom of the root problem, it has been promoted by the same interests that have profited from population increase e.g. property developers, the banking system, which invests in property development, industry, municipal councils etc.[255] 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.[256]


Global fertility rates as of 2020. About a half of the world population lives in nations with sub-replacement fertility.[257]

According to 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.[258] The Institute is also questioning the sincerity of advocates of population control in poor countries who tend to have meetings at expensive high-class hotels in exotic spots.[259]

The Washington Post is also questioning the idea of resource scarcity. According to it, real prices for food were lower in 2011 than 100 years ago, indicating that food became less scarce, in spite of the dramatic population growth during the 20th century.[260]

Scholar, Heather Alberro urges to challenge and reject the overpopulation argument, stating the following reasons:[261]

  • the human population growth is rapidly slowing down
  • the underlying problem is not the number of people, but how resources are distributed
  • the idea of overpopulation could fuel a racist backlash against the population of poor countries

The Wire also noted that proposals of population reduction in poor countries often have racist undertones.[262]


The argument of overpopulation has been criticized as racist since control and reduction of human population is often focused on the global south, instead of on overconsumption and the global north.[263]

By public figures[edit]

Elon Musk is a vocal critic of the idea of overpopulation. According to Musk, proponents of the idea are misled by their immediate impressions from living in dense cities.[264] Because of the negative replacement rates in many countries, he expects that by 2039 the biggest issue will be population collapse, not explosion.[265] Jack Ma expressed a similar opinion.[266]

See also[edit]


  1. ^ Paul Ehrlich; Anne H. Ehrlich (4 August 2008). "Too Many People, Too Much Consumption". Yale Environment 360. Yale School of the Environment. Retrieved 9 January 2021.
  2. ^ Ehrlich, Paul R. Ehrlich & Anne H. (1990). The population explosion. London: Hutchinson. pp. 39–40. ISBN 978-0091745516. Retrieved 20 July 2014. 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.
  3. ^ Ehrlich, Paul R; Ehrlich, Anne H (2004), One with Nineveh: Politics, Consumption, and the Human Future, Island Press/Shearwater Books, pp. 76–180, 256
  4. ^ Ehrlich, Paul R; Ehrlich, Anne H (1991), Healing the Planet: Strategies for Resolving the Environmental Crisis, Addison-Wesley Books, pp. 6–8, 12, 75, 96, 241
  5. ^ Roberts, R.E. (1924). The Theology of Tertullian, Chapter 5 (pp. 79–119) Archived 3 March 2016 at the Wayback Machine. (14 July 2001). Retrieved 29 August 2012.
  6. ^ Joseph A. Tainter (2006). "Archaeology of Overshoot and Collapse". Annual Review of Anthropology. 35: 59–74. doi:10.1146/annurev.anthro.35.081705.123136.
  7. ^ "VII, paragraph 10, lines 8–10". An Essay on the Principle of Population. London: J. Johnson. 1798. 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
  8. ^ a b 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
  9. ^ Cormac Ó Gráda: Famine. A Short History, Princeton University Press 2009, ISBN 978-0-691-12237-3 (pp. 20, 203–206)
  10. ^ Carrington, Damien (18 September 2014). "World population to hit 11bn in 2100 – with 70% chance of continuous rise". The Guardian. Retrieved 19 December 2016.
  11. ^ Gerland, P.; Raftery, A. E.; Ev Ikova, H.; Li, N.; Gu, D.; Spoorenberg, T.; Alkema, L.; Fosdick, B. K.; Chunn, J.; Lalic, N.; Bay, G.; Buettner, T.; Heilig, G. K.; Wilmoth, J. (18 September 2014). "World population stabilization unlikely this century". Science. AAAS. 346 (6206): 234–7. Bibcode:2014Sci...346..234G. doi:10.1126/science.1257469. ISSN 1095-9203. PMC 4230924. PMID 25301627.
  12. ^ World population to keep growing this century, hit 11 billion by 2100 Archived 4 December 2016 at the Wayback Machine. UWToday. 18 September 2014
  13. ^ Harris, Paul (22 October 2011). "Population of world 'could grow to 15bn by 2100'". The Guardian. Retrieved 31 August 2016.
  14. ^ Moody, Oliver (31 August 2017). "Overpopulation is the biggest threat to mankind, Nobel laureates say". The Times. Retrieved 2 September 2017.
  15. ^ Ripple WJ, Wolf C, Newsome TM, Galetti M, Alamgir M, Crist E, Mahmoud MI, Laurance WF (13 November 2017). "World Scientists' Warning to Humanity: A Second Notice" (PDF). BioScience. 67 (12): 1026–1028. doi:10.1093/biosci/bix125.
  16. ^ Jason Hickel (29 January 2019). Bill Gates says poverty is decreasing. He couldn't be more wrong. The Guardian. Retrieved 30 January 2019.
  17. ^ Jones, Campbell; Parker, Martin; Ten Bos, Rene (2005). For Business Ethics. Routledge. p. 101. ISBN 978-0415311359. Critics of neoliberalism have therefore looked at the evidence that documents the results of this great experiment of the past 30 years, in which many markets have been set free. Looking at the evidence, we can see that the total amount of global trade has increased significantly, but that global poverty has increased, with more today living in abject poverty than before neoliberalism.
  18. ^ Haymes, Stephen N.; de Haymes, María V.; Miller, Reuben J., eds. (2015). The Routledge Handbook of Poverty in the United States. London and New York: Routledge. pp. 1 & 2. ISBN 978-0-41-567344-0.
  19. ^ a b c d "The short history of global living conditions and why it matters that we know it". Our World in Data. Retrieved 24 September 2018.
  20. ^ a b "Does population growth lead to hunger and famine?". Our World in Data. Retrieved 24 September 2018.
  21. ^ Ripple, William J.; Wolf, Christopher; Newsome, Thomas M; Barnard, Phoebe; Moomaw, William R (5 November 2019). "World Scientists' Warning of a Climate Emergency". BioScience. doi:10.1093/biosci/biz088. hdl:1808/30278. Retrieved 8 November 2019.
  22. ^ Carrington, Damian (5 November 2019). "Climate crisis: 11,000 scientists warn of 'untold suffering'". The Guardian. Retrieved 8 November 2019.
  23. ^ "Black death 'discriminated' between victims". 29 January 2008. Archived from the original on 20 December 2016. Retrieved 3 November 2008.
  24. ^ Roser, Max; Ritchie, Hannah; Ortiz-Ospina, Esteban (9 May 2013). "World Population Growth". Our World in Data.
  25. ^ Pimentel, David. "Overpopulation and sustainability." Petroleum Review 59 (2006): 34-36.
  26. ^ Hayami, Yujiro, and Vernon W. Ruttan. "Population growth and agricultural productivity." Technological Prospects and Population Trends. Routledge, 2020. 11-69.
  27. ^ Smil, Vaclav (1999). "Detonator of the population explosion" (PDF). Nature. 400 (6743): 415. Bibcode:1999Natur.400..415S. doi:10.1038/22672. S2CID 4301828.
  28. ^ a b "Population seven billion: UN sets out challenges". BBC. 22 May 2013. Retrieved 30 November 2011.
  29. ^ Cassils, J. Anthony. "Overpopulation, sustainable development, and security: Developing an integrated strategy." Population and Environment 25.3 (2004): 171-194.
  30. ^ Moseley, William G. "Reflecting on National Geographic Magazine and academic geography: The September 2005 special issue on Africa." African Geographical Review 24.1 (2005): 93-100.
  31. ^ Asongu, Simplice, and Brian Jingwa. "Population growth and forest sustainability in Africa." International Journal of Green Economics 6.2 (2012): 145-166.
  32. ^ "Current World Population". Worldometers. Retrieved 22 June 2020.
  33. ^ "A Brief Introduction to the History of Climate". Lawrence Berkeley National Laboratories. Retrieved 22 May 2013.
  34. ^ "The Neolithic Agricultural Revolution" (PDF). Council For Economic Education. p. 46. Retrieved 22 May 2013.
  35. ^ "Plague, Plague Information, Black Death Facts, News, Photos". National Geographic. Retrieved 3 November 2008.
  36. ^ "Epidemics and pandemics: their impacts on human history". J. N. Hays (2005). p.46. ISBN 1-85109-658-2
  37. ^ "Historical Estimates of World Population". Archived from the original on 13 October 2013. Retrieved 3 November 2008.
  38. ^ "History of Europe – Demographic and agricultural growth". Encyclopædia Britannica.
  39. ^ "Europe's Black Death is a history lesson in human tragedy – and economic renewal". TIME Europe. 17 July 2000, VOL. 156 NO. 3
  40. ^ "Ming Dynasty: Microsoft Encarta Online Encyclopedia 2009". Archived from the original on 26 January 2009. Retrieved 15 August 2010.CS1 maint: bot: original URL status unknown (link)
  41. ^ "Qing China's Internal Crisis: Land Shortage, Famine, Rural Poverty". Asia for Educators, Columbia University.
  42. ^ J. N. Hays (1998). "The burdens of disease: epidemics and human response in western history.". p 72. ISBN 0-8135-2528-4
  43. ^ "The Story Of... Smallpox – and other Deadly Eurasian Germs". Public Broadcasting Service (PBS).
  44. ^ Nunn, Nathan (27 February 2017). "Understanding the long-run effects of Africa's slave trades". Retrieved 9 February 2021.
  45. ^ a b "International Programs". Archived from the original on 13 October 2013.
  46. ^ "The limits of a Green Revolution?". BBC News. 29 March 2007.
  47. ^ "United Nations, United Nations, Department of Economic and Social Affairs, Population Division (2011): World Population Prospects: The 2010 Revision". Archived from the original on 12 May 2011. Retrieved 25 September 2012.CS1 maint: bot: original URL status unknown (link)
  48. ^ "modelling exponential growth" (PDF).
  49. ^ Benatar, David (2008). Better Never to Have Been: The Harm of Coming into Existence. Oxford University Press. p. 167. ISBN 978-0199549269.
  50. ^ Penfound, William T. "The Problems of Overpopulation". Bios, vol. 39, no. 2, 1968, pp. 56–62. JSTOR, Retrieved 31 January 2020.
  51. ^ Feeney J. Hunter-gatherer land management in the human break from ecological sustainability. The Anthropocene Review. 2019;6(3):223-242. doi:10.1177/2053019619864382
  52. ^ Huesemann, M.H., and J.A. Huesemann (2011). Technofix: Why Technology Won't Save Us or the Environment, "Unintended Consequences of Industrial Agriculture", New Society Publishers, Gabriola Island, Canada, pp. 23–25.
  53. ^ Techno-Fix: Why Technology Won't Save Us Or the Environment By Michael Huesemann, Joyce Huesemann. New Society Publishers. p. 73. despite the fact that hunger and starvation may not be due to food shortages but rather the result of various economic and political factors
  54. ^ McKeown, T. (1988). The Origins of Human Disease, Basil Blackwell, Oxford, UK, pp.60.
  55. ^ Correction for Zahid et al., Agriculture, population growth, and statistical analysis of the radiocarbon record. Proc Natl Acad Sci U S A. 2016;113(18):E2546. doi:10.1073/pnas.1605181113
  56. ^ Cite Warren, Stephen G. "Did agriculture cause the population explosion?." Nature 397.6715 (1999): 101.
  57. ^ Armelagos, George J.; Goodman, Alan H.; Jacobs, Kenneth H. (1 September 1991). "The origins of agriculture: Population growth during a period of declining health". Population and Environment. 13 (1): 9–22. doi:10.1007/BF01256568. ISSN 1573-7810. S2CID 153470610.
  58. ^ Taiz, Lincoln. "Agriculture, plant physiology, and human population growth: past, present, and future." Theoretical and Experimental Plant Physiology 25.3 (2013): 167-181.
  59. ^ 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
  60. ^ Kelly, Karina (13 September 1995). "A Chat with Tim Flannery on Population Control". Australian Broadcasting Corporation. Archived from the original on 13 January 2010. Retrieved 23 April 2010. "Well, Australia has by far the world's least fertile soils".
  61. ^ Grant, Cameron (August 2007). "Damaged Dirt" (PDF). The Advertiser. Archived from the original (PDF) on 6 July 2011. Retrieved 23 April 2010. Australia has the oldest, most highly weathered soils on the planet.
  62. ^ a b c 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
  63. ^ "Human Carrying Capacity is Determined by Food Availability" (PDF). Russel Hopfenberg, Duke University.
  64. ^ Abernathy, Virginia, Population Politics ISBN 0-7658-0603-7
  65. ^ Hardin, Garrett (1974). "Lifeboat Ethics: the Case Against Helping the Poor". Psychology Today. 8: 38–43.
  66. ^ Manning, Richard (7 September 2011). "Richard Manning on the Green Revolution and the End of Cheap Oil" (Interview). Interviewed by Sally Erickson and Timothy Scott Bennett. Retrieved 15 October 2013 – via YouTube.
  67. ^ Quinn, Daniel, Ishmael Bantam/Turner, 1995, ISBN 0613080939
  68. ^ Zerzan, John (2 April 2008). On Modernity and the Technosphere (Speech). Binghamton University.
  69. ^ GJ Armelagos, AH Goodman, KH Jacobs Population and environment - 1991
  70. ^ Rosa, Daniele (2019). "Nel 2050 gli italiani saranno 20 milioni meno secondo l'Onu [Translation: In 2050 the Italians will be 20 million less, according to the UN]". Affaritaliani. Uomini & Affari Srl.
  71. ^ Daniel Quinn (1996). The Story of B, pp. 304–305, Random House Publishing Group, ISBN 0553379011.
  72. ^ Quinn, Daniel: "The Question (ID Number 122)". Retrieved October 2014 from "Archived copy". Archived from the original on 4 March 2016. Retrieved 18 October 2014.CS1 maint: archived copy as title (link).
  73. ^ "World Population Clock: 7.7 Billion People (2019) - Worldometers". Retrieved 28 June 2019.
  74. ^ "U.S. and World Population Clock". Retrieved 5 March 2016.
  75. ^ "Population seven billion: UN sets out challenges". BBC. 26 October 2011. Retrieved 27 October 2011.
  76. ^ Coleman, Jasmine (31 October 2011). "World's 'seven billionth baby' is born". The Guardian. London. Retrieved 31 October 2011.
  77. ^ "7 billion people is a 'serious challenge'". United Press International.
  78. ^ "World Population Clock – Worldometers". Retrieved 1 August 2010.
  79. ^ "International Data Base (IDB) – World Population". 28 June 2010. Archived from the original on 7 July 2010. Retrieved 1 August 2010.
  80. ^ "World Population Prospects:The 2008 Revision" (PDF). Population Division of the Department of Economic and Social Affairs of the United Nations Secretariat. June 2009.
  81. ^ United Nations. "Definition of projection variants". United Nation Population Division. United Nations. Retrieved 9 October 2019.
  82. ^ "World population projected to reach 9.8 billion in 2050, and 11.2 billion in 2100". Population Division of the Department of Economic and Social Affairs of the United Nations Secretariat. June 2017.
  83. ^ "The end of high fertility is near" (PDF). United Nations. Retrieved 9 December 2018.
  84. ^ "World Population Prospects" (PDF). United Nations. Retrieved 9 December 2018.
  85. ^ "joint statement by fifty-eight of the world's scientific academies". Archived from the original on 10 February 2010.
  86. ^ Wilson, E.O. (2002). The Future of Life, Vintage ISBN 0-679-76811-4
  87. ^ a b c Ron Nielsen, The Little Green Handbook: Seven Trends Shaping the Future of Our Planet, Picador, New York (2006) ISBN 978-0-312-42581-4
  88. ^ Pentti Linkola, "Can Life Prevail?", Arktos Media, 2nd Revised ed. 2011. pp. 120–121. ISBN 1907166637
  89. ^ McKie, Robin (25 January 2017). "Biologists think 50% of species will be facing extinction by the end of the century". The Observer.
  90. ^ Leaders from the 1960s: A Biographical Sourcebook of American Activism. Greenwood Press, 1994. 1994. p. 318. ISBN 9780313274145.
  91. ^ Sowell, Thomas (12 February 1998). Julian Simon, combatant in a 200-year war.
  92. ^ a b Williams, Walter (24 February 1999). Population control nonsense Archived 15 May 2016 at the Wayback Machine.
  93. ^ "People and Planet speech". Royal Society of Arts.
  94. ^ David Attenborough – Humans are plague on Earth Archived 20 November 2016 at the Wayback Machine. The Daily Telegraph. 22 January 2013.
  95. ^ "Census intensifies concern in Cairo over soaring population". The Jerusalem Post.
  96. ^ a b Food and Agriculture Organization of the United Nations (2001). Food Insecurity: When People Live With Hunger and Fear Starvation. The State of Food insecurity in the World 2001 Archived 1 December 2016 at the Wayback Machine. FAO, ISBN 92-5-104628-X
  97. ^ a b Shiklomanov, I. A. (2000). "Appraisal and Assessment of World Water Resources". Water International. 25: 11–32. doi:10.1080/02508060008686794. S2CID 4936257.
  98. ^ Jason Hickel. Forget 'developing' poor countries, it's time to 'de-develop' rich countries Archived 1 December 2016 at the Wayback Machine. The Guardian. 23 September 2015.
  99. ^ "Field Listing: Population size". The World Factbook. Retrieved 30 May 2017.
  100. ^ "Field Listing: Total Fertility Rate". The World Factbook. Retrieved 30 May 2017.
  101. ^ "Field Listing: GDP – per capita (PPP)". The World Factbook. Retrieved 30 May 2017.
  102. ^ U.S. National Research Council, Commission on the Science of Climate Change, Washington, D.C. (2001)
  103. ^ Image:Infant mortality vs.jpg
  104. ^ Human overpopulation. Animal Welfare Institute. Retrieved 2014/10/25 from "Human Overpopulation". Archived from the original on 22 October 2016. Retrieved 1 December 2014.
  105. ^ Daily, Gretchen C. and Ellison, Katherine (2003) The New Economy of Nature: The Quest to Make Conservation Profitable, Island Press ISBN 1559631546
  106. ^ Rifkin, Jeremy (24 December 2006). "The risks of too much city in a crowded world". Toronto Star. Archived from the original on 22 May 2012.
  107. ^ Subramanian, Meera (2019). "Anthropocene now: influential panel votes to recognize Earth's new epoch". Nature News. Retrieved 1 March 2020. 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.
  108. ^ Syvitski, Jaia; Waters, Colin N.; Day, John; et al. (2020). "Extraordinary human energy consumption and resultant geological impacts beginning around 1950 CE initiated the proposed Anthropocene Epoch". Communications Earth & Environment. 1 (32). doi:10.1038/s43247-020-00029-y. S2CID 222415797. 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.
  109. ^ "UN World Population Report 2001" (PDF). p. 31. Retrieved 16 December 2008.
  110. ^ "Booming nations 'threaten Earth'". BBC News (12 January 2006).
  111. ^ "State of the World 2006: China and India Hold World in Balance Archived 15 April 2016 at the Wayback Machine". Worldwatch Institute. 11 January 2006.
  112. ^ "Effects of Over-Consumption and Increasing Populations Archived 8 June 2008 at the Wayback Machine". 26 September 2001. Retrieved 19 June 2007.
  113. ^ John T. Houghton (2004)."Global warming: the complete briefing Archived 3 May 2016 at the Wayback Machine". Cambridge University Press. p.326. ISBN 0-521-52874-7
  114. ^ "Once taboo, population enters climate debate". The Independent. London. 5 December 2009. Retrieved 21 January 2010.
  115. ^ Best, Steven (2014). The Politics of Total Liberation: Revolution for the 21st Century. Palgrave Macmillan. p. 160. ISBN 978-1137471116. By 2050 the human population will top 9 billion, and world meat consumption will likely double.
  116. ^ Devlin, Hannah (19 July 2018). "Rising global meat consumption 'will devastate environment'". The Guardian. Retrieved 28 September 2019.
  117. ^ We Are Breeding Ourselves to Extinction. Chris Hedges for Truthdig. 8 March 2009
  118. ^ Ceballos, Gerardo; Ehrlich, Paul R.; Barnosky, Anthony D.; García, Andrés; Pringle, Robert M.; Palmer, Todd M. (2015). "Accelerated modern human–induced species losses: Entering the sixth mass extinction". Science Advances. 1 (5): e1400253. Bibcode:2015SciA....1E0253C. doi:10.1126/sciadv.1400253. PMC 4640606. PMID 26601195.
  119. ^ Pimm, S. L.; Jenkins, C. N.; Abell, R.; Brooks, T. M.; Gittleman, J. L.; Joppa, L. N.; Raven, P. H.; Roberts, C. M.; Sexton, J. O. (30 May 2014). "The biodiversity of species and their rates of extinction, distribution, and protection" (PDF). Science. 344 (6187): 1246752. doi:10.1126/science.1246752. PMID 24876501. S2CID 206552746. Retrieved 15 December 2016. The overarching driver of species extinction is human population growth and increasing per capita consumption.
  120. ^ Ceballos, Gerardo; Ehrlich, Paul R; Dirzo, Rodolfo (23 May 2017). "Biological annihilation via the ongoing sixth mass extinction signaled by vertebrate population losses and declines". PNAS. 114 (30): E6089–E6096. doi:10.1073/pnas.1704949114. PMC 5544311. PMID 28696295. 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.
  121. ^ Andermann, Tobias; Faurby, Søren; Turvey, Samuel T.; Antonelli, Alexandre; Silvestro, Daniele (1 September 2020). "The past and future human impact on mammalian diversity". Science Advances. 6 (36): eabb2313. doi:10.1126/sciadv.abb2313. ISSN 2375-2548. PMC 7473673. PMID 32917612. Retrieved 9 October 2020. CC-BY icon.svg Text and images are available under a Creative Commons Attribution 4.0 International License.
  122. ^ Weston, Phoebe (13 January 2021). "Top scientists warn of 'ghastly future of mass extinction' and climate disruption". The Guardian. Retrieved 13 January 2021. Large populations and their continued growth drive soil degradation and biodiversity loss, the new paper warns. “More people means that more synthetic compounds and dangerous throwaway plastics are manufactured, many of which add to the growing toxification of the Earth. It also increases the chances of pandemics that fuel ever-more desperate hunts for scarce resources.”
  123. ^ Pimm, Stuart L.; Russell, Gareth J.; Gittleman, John L.; Brooks, Thomas M. (1995). "The Future of Biodiversity". Science. 269 (5222): 347–350. Bibcode:1995Sci...269..347P. doi:10.1126/science.269.5222.347. PMID 17841251. S2CID 35154695.
  124. ^ "Citizens arrest Archived 27 September 2016 at the Wayback Machine". The Guardian. 11 July 2007.
  125. ^ "Population Bomb Author's Fix For Next Extinction: Educate Women Archived 10 November 2013 at the Wayback Machine". Scientific American. 12 August 2008.
  126. ^ Sutter, John D. (12 December 2016). "How to stop the sixth mass extinction". CNN. Retrieved 19 December 2016.
  127. ^ Stokstad, Erik (5 May 2019). "Landmark analysis documents the alarming global decline of nature". Science. AAAS. Retrieved 11 August 2020. 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.)
  128. ^ Watts, Jonathan (6 May 2019). "Human society under urgent threat from loss of Earth's natural life". The Guardian. Retrieved 18 May 2019.
  129. ^ Greenfield, Patrick (9 September 2020). "Humans exploiting and destroying nature on unprecedented scale – report". The Guardian. Retrieved 10 September 2020.
  130. ^ Lewis, Sophie (9 September 2020). "Animal populations worldwide have declined by almost 70% in just 50 years, new report says". CBS News. Retrieved 10 September 2020.
  131. ^ Saxena, Pallavi, and Anju Srivastava. Air Pollution and Environmental Health. Vol. 20. Springer Nature, 2020.
  132. ^ International Energy Outlook 2000, Energy Information Administration, Office of Integrated Analysis and Forecasting, U.S. Department of Energy, Washington, D.C. (2000)
  133. ^ "The world in 2050:Impact of global growth on carbon emissions". 30 October 2006. Retrieved 30 November 2011.
  134. ^ Wynes, Seth; Nicholas, Kimberly A. (28 November 2017). "The climate mitigation gap: education and government recommendations miss the most effective individual actions". Environmental Research Letters. 12 (7): 074024. Bibcode:2017ERL....12g4024W. doi:10.1088/1748-9326/aa7541.
  135. ^ Lu, Max. "OVERPOPULATION STRESSES RESOURCES, WHICH IN TURN STRESSES PEOPLE." Natural Resource Conflicts: From Blood Diamonds to Rainforest Destruction [2 volumes]: From Blood Diamonds to Rainforest Destruction (2016): 10.
  136. ^ Sato, Chloe F.; Lindenmayer, David B. (2018). "Meeting the Global Ecosystem Collapse Challenge". Conservation Letters. 11 (1): e12348. doi:10.1111/conl.12348.
  137. ^ Bland, L.; Rowland, J.; Regan, T.; Keith, D.; Murray, N.; Lester, R.; Linn, M.; Rodríguez, J.P.; Nicholson, E. (2018). "Developing a standardized definition of ecosystem collapse for risk assessment". Frontiers in Ecology and the Environment. 16 (1): 29–36. doi:10.1002/fee.1747.
  138. ^ Pinsky, Malin L.; Byler, David (22 August 2015). "Fishing, fast growth and climate variability increase the risk of collapse". Proc. R. Soc. B. 282 (1813): 20151053. doi:10.1098/rspb.2015.1053. ISSN 0962-8452. PMC 4632620. PMID 26246548.
  139. ^ "Another Inconvenient Truth: The World's Growing Population Poses a Malthusian Dilemma Archived 25 December 2013 at the Wayback Machine". Scientific American (2 October 2009).
  140. ^ David Pimentel, et al. "Will Limits of the Earth's Resources Control Human Numbers?" Archived 10 July 2016 at the Wayback Machine,
  141. ^ Lester R. Brown, Gary Gardner, Brian Halweil (September 1998). Worldwatch Paper #143: Beyond Malthus: Sixteen Dimensions of the Population Problem Archived 3 March 2016 at the Wayback Machine, Worldwatch Institute, ISBN 1-878071-45-9
  142. ^ a b "News". Archived from the original on 4 March 2016. Retrieved 16 July 2014.
  143. ^ "Earth's natural wealth: an audit". New Scientist. 23 May 2007. Retrieved 30 November 2011.
  144. ^ "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". The Independent. UK. 18 January 2011. Retrieved 30 November 2011.
  145. ^ "Misleading Math about the Earth: Scientific American". Retrieved 30 November 2011.
  146. ^ "1. How have ecosystems changed?". 17 October 2011. Retrieved 30 November 2011.
  147. ^ a b "Ecosystem Change: Scientific Facts on Ecosystem Change". 17 October 2011. Retrieved 30 November 2011.
  148. ^ "3. How have ecosystem changes affected human well-being and poverty alleviation?". 17 October 2011. Retrieved 30 November 2011.
  149. ^ "UN World Population Report 2001" (PDF). p. 34. Retrieved 16 December 2008.
  150. ^ "UN World Population Report 2001" (PDF). p. 34. Retrieved 16 December 2008.
  151. ^ a b "French-run water plant launched in Israel". 28 December 2005. Archived from the original on 13 December 2009. Retrieved 30 November 2011.
  152. ^ "Black & Veatch-Designed Desalination Plant Wins Global Water Distinction". Archived from the original on 24 March 2010.
  153. ^ Brown, Lester R. and Halweil, Brian (23 September 1999). Population Outrunning Water Supply as World Hits 6 Billion. Worldwatch Institute.
  154. ^ Fred Pearce (2007). When the Rivers Run Dry: Water—The Defining Crisis of the Twenty-first Century. Beacon Press. ISBN 978-0-8070-8573-8.
  155. ^ Worldwatch, The (27 April 2012). Outgrowing the Earth: The Food Security Challenge in an Age of Falling Water Tables and Rising Temperatures: Books: Lester R. Brown. ISBN 978-0393060706.
  156. ^ "South Asia news – India grows a grain crisis". Asia Times. 21 July 2006. Retrieved 30 November 2011.
  157. ^ "Black & Veatch-Designed Desalination Plant Wins Global Water Distinction". 4 May 2006. Archived from the original on 24 March 2010. Retrieved 30 November 2011.
  158. ^ "The Coming Wars for Water". Report Syndication. 12 October 2019.
  159. ^ "Domesticating the World: Conversion of Natural Ecosystems". World Resources Institute. September 2000. Archived from the original on 19 February 2007.
  160. ^ "Grasslands in Pieces: Modification and Conversion Take a Toll". World Resources Institute. December 2000. Archived from the original on 19 February 2007.
  161. ^ "GLOBIO, an initiative of the United Nations Environment Programme (Archive)". 30 June 2007. Archived from the original on 30 June 2007. Retrieved 30 November 2011.
  162. ^ Young, A. (1999). "Is there Really Spare Land? A Critique of Estimates of Available Cultivable Land in Developing Countries". Environment, Development and Sustainability. 1: 3–18. doi:10.1023/A:1010055012699. S2CID 153970029.
  163. ^ Tagliabue, John (7 November 2008). "The Dutch seek to claim more land from the sea". The New York Times. Retrieved 9 February 2017.
  164. ^ Shepard, Wade (25 August 2015). ""The gift from the sea": through land reclamation, China keeps growing and growing". CityMetric. Retrieved 9 February 2017.
  165. ^ Cooke, Jeremy (19 June 2007). "Vertical farming in the big Apple". BBC News. Retrieved 20 May 2010.
  166. ^ "Overpopulation: The Making of a Myth". Retrieved 13 February 2010.
  167. ^ Haynes, Michael; Husan, Rumy (2000). "National inequality and the catch-up period: Some "growth alone" scenarios"". Journal of Economic Issues. 34 (3): 693–705. doi:10.1080/00213624.2000.11506301. JSTOR 4227593. S2CID 155273403. In a world that now produces more food than is necessary to feed all its population [UN 1994], there is no excuse for hunger and starvation.
  168. ^ Gilland, B. (2002). "World population and food supply". Food Policy. 27: 47–63. doi:10.1016/S0306-9192(02)00002-7.
  169. ^ "Human Appropriation of the World's Food Supply". 15 December 2000. Archived from the original on 4 December 2011. Retrieved 30 November 2011.
  170. ^ "UN World Population Report 2001" (PDF). p. 38. Retrieved 16 December 2008.
  171. ^ a b c Food and Agriculture Organization Economic and Social Development Department. "The State of Food Insecurity in the World, 2018 : Building resilence for peace and food security. " . Food and Agriculture Organization of the United Nations, 2018, p. 1.
  172. ^ "The truth about the environment". The Economist. 2 August 2001.
  173. ^ a b Pimm, Stuart; Harvey, Jeff (2001). "No need to worry about the future" (PDF). Nature. 414 (6860): 149. Bibcode:2001Natur.414..149P. doi:10.1038/35102629. S2CID 205022759. Archived from the original (PDF) on 10 June 2007.
  174. ^ "3. How have ecosystem changes affected human well-being and poverty alleviation?". 17 October 2011. Retrieved 30 November 2011.
  175. ^ "'Peak Oil' and the German Government: Military Study Warns of a Potentially Drastic Oil Crisis". Der Spiegel.
  176. ^ "Global threat to food supply as water wells dry up, warns top environment expert Archived 8 December 2016 at the Wayback Machine". The Guardian. 6 July 2013.
  177. ^ "World faces 'perfect storm' of problems by 2030, chief scientist to warn Archived 14 November 2016 at the Wayback Machine". The Guardian. 18 March 2009.
  178. ^ "Global crisis 'to strike by 2030' Archived 15 November 2016 at the Wayback Machine". BBC News. 19 March 2009.
  179. ^ "Global food production will have to increase 70% for additional 2.3 billion people by 2050 Archived 10 March 2016 at the Wayback Machine". 24 September 2009.
  180. ^ Heidelberger Institut fur International Konfliktforschung, Konfliktbarometer 2003: 12. Jarlickhe Konfliktanalyse University of Heidelberg, Germany (2004)
  181. ^ Champion, Tony (2005). "Chapter 4: Demographic transformations". In Daniels, Peter; Bradshaw, Michael; Shaw, Denis; Sidaway, James (eds.). An Introduction to Human Geography Issues for the 21st Century Second edition. Pearson Education. pp. 88–111. ISBN 978-0-131-21766-9.
  182. ^ a b Turchin P, Korotayev A (2006). "Population Dynamics and Internal Warfare: A Reconsideration". Social Evolution & History. 5 (2): 112–147.
  183. ^ Korotayev A, Malkov A, Khaltourina D (2006). Introduction to Social Macrodynamics. Secular Cycles and Millennial Trends. Moscow: URSS. ISBN 5-484-00559-0.
  184. ^ Korotayev AV, Khaltourina DA (2006). Introduction to Social Macrodynamics: Secular Cycles and Millennial Trends in Africa. Moscow: URSS. ISBN 5-484-00560-4.
  185. ^ Carrington, Damian (21 May 2018). "Humans just 0.01% of all life but have destroyed 83% of wild mammals – study". The Guardian. Retrieved 13 July 2019.
  186. ^ Baillie, Jonathan; Zhang, Ya-Ping (2018). "Space for nature". Science. 361 (6407): 1051. Bibcode:2018Sci...361.1051B. doi:10.1126/science.aau1397. PMID 30213888.
  187. ^ George Monbiot (19 November 2015). "There's a population crisis all right. But probably not the one you think". The Guardian. Retrieved 25 November 2020.
  188. ^ UNEP, Global Environmental Outlook 2000, Earthscan Publications, London, UK (1999)
  189. ^ Polgreen, Lydia (11 February 2007). "Trees and crops reclaim desert in Niger". International Herald Tribune. Retrieved 30 November 2011.
  190. ^ ""Emerging Infectious Diseases" by Mark E.J. Woolhouse and Sonya Gowtage-Sequeria". Retrieved 30 November 2011.
  191. ^ "WHO Infectious Diseases Report". Archived from the original on 20 November 2011. Retrieved 30 November 2011.
  192. ^ McGranahan, G.; Lewin, S.; Fransen, T.; Hunt, C.; Kjellén, M.; Pretty, J.; Stephens, C.; Virgin, I. (2000). "News and notes: Environmental change and human health in countries of Africa, the Caribbean and the Pacific". Global Change and Human Health. 1: 9. doi:10.1023/A:1011567429284. S2CID 151010794.
  193. ^ "Wastewater Pollution in China". Archived from the original on 29 July 2012. Retrieved 30 November 2011.
  194. ^ "Clean water could save millions of lives". Archived from the original on 26 December 2013. Retrieved 9 July 2014.
  195. ^ American Council for the United Nations University (2002)
  196. ^ Huxley, Aldous. "Brave New World Revisited: overpopulation". Retrieved 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.)
  197. ^ "World Population Prospects: The 2017 Revision" (PDF). United Nations, Department of Economic and Social Affairs, Population Division. 2017. Archived from the original (PDF) on 3 December 2018. Retrieved 2 December 2018.
  198. ^ "World Population Clock – Worldometers". Retrieved 30 November 2011.
  199. ^ "International Data Base (IDB) – World Population". Archived from the original on 7 July 2010. Retrieved 30 November 2011.
  200. ^ "Archived copy". Archived from the original on 29 April 2011. Retrieved 4 December 2009.CS1 maint: archived copy as title (link)
  201. ^ a b "World Population Prospects – Population Division". United Nations. Retrieved 29 November 2017.
  202. ^ Walter Greiling: Wie werden wir leben? ("How are we going to live?") Econ publishers, Munich 1954
  203. ^ Myrskylä, M.; Kohler, H. P.; Billari, F. C. (2009). "Advances in development reverse fertility declines". Nature. 460 (7256): 741–743. Bibcode:2009Natur.460..741M. doi:10.1038/nature08230. PMID 19661915. S2CID 4381880.
  204. ^ Gaddy, Hampton Gray (20 January 2021). "A decade of TFR declines suggests no relationship between development and sub-replacement fertility rebounds". Demographic Research. 44: 125–142. doi:10.4054/DemRes.2021.44.5. ISSN 1435-9871.
  205. ^ King, M.; Elliott, C. (1996). "Averting a world food shortage: Tighten your belts for CAIRO II". BMJ. 313 (7063): 995–997. doi:10.1136/bmj.313.7063.995. PMC 2352328. PMID 8892423.
  206. ^ "World Resources Institute". Archived from the original on 17 January 2012. Retrieved 30 November 2011.
  207. ^ Morales, Alex (24 October 2006). "Canada". Bloomberg. Retrieved 30 November 2011.
  208. ^ "WWF – Living Planet Report 2006". Retrieved 30 November 2011.
  209. ^ "WWF Living planet report". Retrieved 30 November 2011.
  210. ^ "Data and Methodology". Retrieved 6 March 2020.
  211. ^ Martin, Roger (2010). "Stopping at two children is better for the planet". BBC HARDtalk. Interviewed by Carrie Gracie
  212. ^ Carrington, Damian (30 September 2014). "Earth has lost half of its wildlife in the past 40 years, says WWF". The Guardian. Retrieved 3 January 2017.
  213. ^ "Publications – Global Footprint Network". Retrieved 17 September 2017.
  214. ^ Jeroen C.J.M. van den Bergh; Harmen Verbruggen (1999). "Spatial sustainability, trade and indicators: an evaluation of the 'ecological footprint'" (PDF). Ecological Economics. 29 (1): 61–72. doi:10.1016/S0921-8009(99)00032-4. Archived from the original (PDF) on 9 October 2007.
  215. ^ "Planning and Markets: Peter Gordon and Harry W. Richardson". Archived from the original on 27 June 2010. Retrieved 30 November 2011.
  216. ^ Cohen, J.E. (1995). How many people can the earth support? W.W. Norton & Company, New York, NY, USA.
  217. ^ Van Den Bergh, Jeroen C. J. M.; Rietveld, Piet (2004). "Reconsidering the Limits to World Population: Meta-analysis and Meta-prediction". BioScience. 54 (3): 195. doi:10.1641/0006-3568(2004)054[0195:RTLTWP]2.0.CO;2. ISSN 0006-3568.
  218. ^ Carrington, Damian (22 March 2018). "Paul Ehrlich: 'Collapse of civilisation is a near certainty within decades'". The Guardian. Retrieved 8 August 2020.
  219. ^ A PLANET OF 3 BILLION | Kirkus Reviews.
  220. ^ Sasser, Jade (13 November 2018). On infertile ground : population control and women's rights in the era of climate change. New York. ISBN 978-1-4798-7343-2. OCLC 1029075188.
  221. ^ "Principal Agglomerations of the World". Retrieved 30 November 2011.
  222. ^ Lewis, Mark (11 June 2007). "Megacities of the Future". Forbes. Retrieved 30 November 2011.
  223. ^ "68% of the world population projected to live in urban areas by 2050, says UN". United Nations Department of Economic and Social Affairs. 16 March 2018. Retrieved 9 November 2018.
  224. ^ "Nigeria: Lagos, the mega-city of slums". Archived from the original on 18 February 2011.
  225. ^ Whitehouse, David (19 May 2005). "Half of humanity set to go urban". BBC News. Retrieved 30 November 2011.
  226. ^ "Planet of Slums – The Third World's Megacities". Retrieved 30 November 2011.
  227. ^ Huesemann, M.H. and Huesemann, J.A. (2011). Techno-fix: Why Technology Won't Save Us or the Environment, New Society Publishers, Gabriola Island, Canada
  228. ^ Ehrlich, Paul R; Ehrlich, Anne H (2004), One with Nineveh: Politics, Consumption, and the Human Future, Island Press/Shearwater Books, pp. 138–180 (chapter 5)
  229. ^ "Population growth driving climate change, poverty: experts Archived 23 May 2012 at the Wayback Machine". Agence France-Presse (21 September 2009).
  230. ^ Finer, Lawrence B.; Henshaw, Stanley K. (2006). "Disparities in Rates of Unintended Pregnancy In the United States, 1994 and 2001". Perspectives on Sexual and Reproductive Health. 38 (2): 90–96. doi:10.1363/3809006. PMID 16772190.
  231. ^ "Netherlands Again Number One Donor to United Nations Population Fund". United Nations Population Fund (UNFPA).
  232. ^ "Maternal mortality ratio falling too slowly to meet goal Archived 31 October 2013 at the Wayback Machine". WHO (12 October 2007).
  233. ^ Fornos, Werner (10 December 2001). "Q: should the United Nations support more family-planning services for poor countries?". Insight on the News.
  234. ^ "Population Matters search on 'reproductive rights'". Population Matters.[permanent dead link]
  235. ^ Pollack Petchesky, Rosalind. "From population control to reproductive rights: Feminist fault lines." Reproductive Health Matters 3.6 (1995): 152-161.
  236. ^ Ehrlich, Paul R; Ehrlich, Anne H (2004), One with Nineveh: Politics, Consumption, and the Human Future, Island Press/Shearwater Books, pp. 181–205 (chapter 6)
  237. ^ Ehrlich, Paul R.; Ehrlich, Anne H.; Daily, Gretchen C. (1995), The Stork and the Plow: The Equity Answer to the Human Dilemma, Grosset/Putnam Books
  238. ^ Eos magazine, April 2018
  239. ^ Lifeblood: How to Change the World One Dead Mosquito at a Time, Alex Perry p9
  240. ^ a b Ryerson, William N. (2010). The Post Carbon Reader: Managing the 21st Century's Sustainability Crises, "Ch.12: Population: The Multiplier of Everything Else". Healdsburg, Calif.: Watershed Media. pp. 153–174. ISBN 978-0970950062.
  241. ^ "Birth rates 'must be curbed to win war on global poverty'". The Independent. London. 31 January 2007. Archived from the original on 19 January 2008. Retrieved 20 May 2010.
  242. ^ Vinay Lal. Indira Gandhi Archived 29 July 2016 at the Wayback Machine, UCLA College of Letters and Science
  243. ^ "'Cars for sterilisation' campaign". 1 July 2011. Archived from the original on 4 March 2016 – via
  244. ^ Kunzig, Robert, "A world with 11 billion people? New population projections shatter earlier estimates." National Geographic, 18 September 2014, "A World with 11 Billion People? New Population Projections Shatter Earlier Estimates". 19 September 2014. Archived from the original on 19 December 2016. Retrieved 25 February 2015.
  245. ^ The High Frontier (1976, 2000) Gerard K. O'Neill, Apogee Books ISBN 1-896522-67-X
  246. ^ Marshall Savage, (1992, 1994) The Millennial Project: Colonizing the Galaxy in Eight Easy Steps. Little, Brown. ISBN 0-316-77163-5
  247. ^ The Telegraph. Stephen Hawking: mankind must move to outer space within a century. (August 2010) "Archived copy". Archived from the original on 25 October 2014. Retrieved 25 October 2014.CS1 maint: archived copy as title (link)
  248. ^ a b Greetings, Carbon-Based Bipeds! (1999) Arthur C. Clarke, Voyager ISBN 0-00-224698-8
  249. ^ The Good Earth Is Dying (1971) Isaac Asimov (published in Der Spiegel)
  250. ^ Mining the Sky (1996) John S. Lewis. Addison Wesley. ISBN 0-201-47959-1
  251. ^ O'Neill, Gerard K. (1981). 2081: A Hopeful View of the Human Future. Simon and Schuster. ISBN 978-0-671-44751-9.
  252. ^ "UN Habitat calling urban living 'a good thing". BBC News. 27 June 2007. Retrieved 30 November 2011.
  253. ^ "National Geographic Magazine; Special report 2008: Changing Climate (Village Green-article by Michelle Nijhuis)". 29 September 2011. Retrieved 30 November 2011.
  254. ^ "UN Habitat calling to rethink urban planning". Archived from the original on 7 August 2011. Retrieved 30 November 2011.
  255. ^ Ehrlich, Population Bomb 1968 p.152-p.53
  256. ^ "David Suzuki fires off from the 'death zone' at Trudeau, Weaver and a broken system". National Observer. 5 March 2018.
  257. ^ "Figure 8: Population by Total Fertility (millions)" in World Population Prospects, the 2010 Revision. United Nations, Department of Economic and Social Affairs, Population Division (2011)
  258. ^
  259. ^
  260. ^
  261. ^ Alberro, Heather. "Why we should be wary of blaming 'overpopulation' for the climate crisis". The Conversation. Retrieved 31 December 2020.
  262. ^
  263. ^ Jordan Dyett; Cassidy Thomas (January 2019). "Overpopulation Discourse: Patriarchy, Racism, and the Specter of Ecofascism". Perspectives on Global Development and Technology. 18 (1–2): 205–224. doi:10.1163/15691497-12341514.
  264. ^
  265. ^
  266. ^

Further reading[edit]


Academic journals[edit]

Debate on the consequences of overpopulation[edit]

Media publications[edit]

External links[edit]

External video
video icon Could We Control Human Overpopulation? BBC Earth Lab on YouTube
video icon Sir David Attenborough on Overpopulation on YouTube