In demographics, the world population is the total number of humans currently living, and was estimated to have reached 7.7 billion people as of April 2019. It took over 200,000 years of human history for the world's population to reach 1 billion, and only 200 years more to reach 7 billion.
The world population has experienced continuous growth following the Great Famine of 1315–1317 and the end of the Black Death in 1350, when it was near 370 million. The highest global population growth rates, with increases of over 1.8% per year, occurred between 1955 and 1975—peaking to 2.1% between 1965 and 1970. The growth rate declined to 1.2% between 2010 and 2015 and is projected to decline further in the course of the 21st century. However, the global population is still increasing and is projected to reach about 10 billion in 2050 and more than 11 billion in 2100.
Total annual births were highest in the late 1980s at about 139 million, and as of 2011 were expected to remain essentially constant at a level of 135 million, while deaths numbered 56 million per year and were expected to increase to 80 million per year by 2040. The median age of the world's population was estimated to be 30.4 years in 2018. In mid-2019, the United Nations estimated that the world population had reached 7,713,468,000.
|World population (millions, UN estimates)|
|#||Top ten most populous countries||2000||2015||2030|
Population by region
Six of the Earth's seven continents are permanently inhabited on a large scale. Asia is the most populous continent, with its 4.54 billion inhabitants accounting for 60% of the world population. The world's two most populated countries, China and India, together constitute about 36% of the world's population. Africa is the second most populated continent, with around 1.28 billion people, or 16% of the world's population. Europe's 742 million people make up 10% of the world's population as of 2018, while the Latin American and Caribbean regions are home to around 651 million (9%). Northern America, primarily consisting of the United States and Canada, has a population of around 363 million (5%), and Oceania, the least populated region, has about 41 million inhabitants (0.5%). Though it is not permanently inhabited by any fixed population, Antarctica has a small, fluctuating international population based mainly in polar science stations. This population tends to rise in the summer months and decrease significantly in winter, as visiting researchers return to their home countries.
Population by continent
|Most populous country||Most populous city (metropolitan area)|
||35,676,000/13,634,685 – |
186,987,000 ||21,000,000 – |
approx. 112 million in Europe)
|16,855,000/12,506,468 – |
324,991,600 ||23,723,696/8,537,673 – |
209,567,000 ||27,640,577/11,316,149 – |
24,458,800 ||5,005,400 – |
|0.004 in summer
|N/A||1,200 (non-permanent, varies) – McMurdo Station|
Estimates of world population by their nature are an aspect of modernity, possible only since the Age of Discovery. Early estimates for the population of the world date to the 17th century: William Petty in 1682 estimated world population at 320 million (modern estimates ranging close to twice this number); by the late 18th century, estimates ranged close to one billion (consistent with modern estimates). More refined estimates, broken down by continents, were published in the first half of the 19th century, at 600 to 1000 million in the early 1800s and at 800 to 1000 million in the 1840s.
Ancient and post-classical history
Estimates of the population of the world at the time agriculture emerged in around 10,000 BC have ranged between 1 million and 15 million. Even earlier, genetic evidence suggests humans may have gone through a population bottleneck of between 1,000 and 10,000 people about 70,000 BC, according to the Toba catastrophe theory. By contrast, it is estimated that around 50–60 million people lived in the combined eastern and western Roman Empire in the 4th century AD.
The Plague of Justinian, which first emerged during the reign of the Roman emperor Justinian, caused Europe's population to drop by around 50% between the 6th and 8th centuries AD. The population of Europe was more than 70 million in 1340. The Black Death pandemic of the 14th century may have reduced the world's population from an estimated 450 million in 1340 to between 350 and 375 million in 1400; it took 200 years for population figures to recover. The population of China decreased from 123 million in 1200 to 65 million in 1393, presumably from a combination of Mongol invasions, famine, and plague.
Starting in AD 2, the Han Dynasty of ancient China kept consistent family registers in order to properly assess the poll taxes and labor service duties of each household. In that year, the population of Western Han was recorded as 57,671,400 individuals in 12,366,470 households, decreasing to 47,566,772 individuals in 9,348,227 households by AD 146, towards the End of the Han Dynasty. At the founding of the Ming Dynasty in 1368, China's population was reported to be close to 60 million; toward the end of the dynasty in 1644, it may have approached 150 million. England's population reached an estimated 5.6 million in 1650, up from an estimated 2.6 million in 1500. New crops that were brought to Asia and Europe from the Americas by Portuguese and Spanish colonists in the 16th century are believed to have contributed to population growth. Since their introduction to Africa by Portuguese traders in the 16th century, maize and cassava have similarly replaced traditional African crops as the most important staple food crops grown on the continent.
The pre-Columbian population of the Americas is uncertain; historian David Henige called it "the most unanswerable question in the world." By the end of the 20th century, scholarly consensus favored an estimate of roughly 55 million people, but numbers from various sources have ranged from 10 million to 100 million. Encounters between European explorers and populations in the rest of the world often introduced local epidemics of extraordinary virulence. According to the most extreme scholarly claims, as many as 90% of the Native American population of the New World died of Old World diseases such as smallpox, measles, and influenza. Over the centuries, the Europeans had developed high degrees of immunity to these diseases, while the indigenous peoples had no such immunity.
During the European Agricultural and Industrial Revolutions, the life expectancy of children increased dramatically. The percentage of the children born in London who died before the age of five decreased from 74.5% in 1730–1749 to 31.8% in 1810–1829. Between 1700 and 1900, Europe's population increased from about 100 million to over 400 million. Altogether, the areas populated by people of European descent comprised 36% of the world's population in 1900.
Population growth in the West became more rapid after the introduction of vaccination and other improvements in medicine and sanitation. Improved material conditions led to the population of Britain increasing from 10 million to 40 million in the 19th century. The population of the United Kingdom reached 60 million in 2006. The United States saw its population grow from around 5.3 million in 1800 to 106 million in 1920, exceeding 307 million in 2010.
The first half of the 20th century in Imperial Russia and the Soviet Union was marked by a succession of major wars, famines and other disasters which caused large-scale population losses (approximately 60 million excess deaths). After the collapse of the Soviet Union, Russia's population declined significantly – from 150 million in 1991 to 143 million in 2012 – but by 2013 this decline appeared to have halted.
Many countries in the developing world have experienced extremely rapid population growth since the early 20th century, due to economic development and improvements in public health. China's population rose from approximately 430 million in 1850 to 580 million in 1953, and now stands at over 1.3 billion. The population of the Indian subcontinent, which was about 125 million in 1750, increased to 389 million in 1941; today, India, Pakistan and Bangladesh are collectively home to about 1.63 billion people. Java had about 5 million inhabitants in 1815; its present-day successor, Indonesia, now has a population of over 140 million. In just one hundred years, the population of Brazil decupled (x10), from about 17 million in 1900, or about 1% of the world population in that year, to about 176 million in 2000, or almost 3% of the global population in the very early 21st century. Mexico's population grew from 13.6 million in 1900 to about 112 million in 2010. Between the 1920s and 2000s, Kenya's population grew from 2.9 million to 37 million.
Milestones by the billions
|World population milestones in billions (USCB estimates)|
It is estimated that the world population reached one billion for the first time in 1804. It was another 123 years before it reached two billion in 1927, but it took only 33 years to reach three billion in 1960. Thereafter, the global population reached four billion in 1974, five billion in 1987, six billion in 1999 and, according to the United States Census Bureau, seven billion in March 2012. The United Nations, however, estimated that the world population reached seven billion in October 2011.
According to current projections, the global population will reach eight billion by 2024, and is likely to reach around nine billion by 2042. Alternative scenarios for 2050 range from a low of 7.4 billion to a high of more than 10.6 billion. Projected figures vary depending on underlying statistical assumptions and the variables used in projection calculations, especially the fertility variable. Long-range predictions to 2150 range from a population decline to 3.2 billion in the "low scenario", to "high scenarios" of 24.8 billion. One extreme scenario predicted a massive increase to 256 billion by 2150, assuming the global fertility rate remained at its 1995 level of 3.04 children per woman; however, by 2010 the global fertility rate had declined to 2.52.
There is no estimation for the exact day or month the world's population surpassed one or two billion. The points at which it reached three and four billion were not officially noted, but the International Database of the United States Census Bureau placed them in July 1959 and April 1974 respectively. The United Nations did determine, and commemorate, the "Day of 5 Billion" on 11 July 1987, and the "Day of 6 Billion" on 12 October 1999. The Population Division of the United Nations declared the "Day of 7 Billion" to be 31 October 2011.
As of 2012, the global sex ratio is approximately 1.01 males to 1 female. The greater number of men is possibly due to the significant sex imbalances evident in the Indian and Chinese populations. Approximately 26.3% of the global population is aged under 15, while 65.9% is aged 15–64 and 7.9% is aged 65 or over. The median age of the world's population was estimated to be 29.7 years in 2014, and is expected to rise to 37.9 years by 2050.
According to the World Health Organization, the global average life expectancy is 71.4 years as of 2015, with women living an average of 74 years and men approximately 69 years. In 2010, the global fertility rate was estimated at 2.52 children per woman. In June 2012, British researchers calculated the total weight of Earth's human population as approximately 287 million tonnes, with the average person weighing around 62 kilograms (137 lb).
The CIA estimated nominal 2013 gross world product at US$74.31 trillion, giving an annual global per capita figure of around US$10,500. Around 1.29 billion people (18.4% of the world population) live in extreme poverty, subsisting on less than US$1.25 per day; approximately 870 million people (12.25%) are undernourished. 83% of the world's over-15s are considered literate. In June 2014, there were around 3.03 billion global Internet users, constituting 42.3% of the world population.
The Han Chinese are the world's largest single ethnic group, constituting over 19% of the global population in 2011. The world's most-spoken first languages are Mandarin Chinese (spoken by 12.44% of the world's population), Spanish (4.85%), English (4.83%), Arabic (3.25%) and Hindustani (2.68%). The world's largest religion is Christianity, whose adherents account for 31% of the global population; Islam is the second-largest religion, accounting for 24.1%, and Hinduism the third, accounting for 13.78%. In 2005, around 16% of the global population were reported to be non-religious.
Largest populations by country
10 most populous countries
|Rank||Country / Territory||Population||% of world|
|1||1,400,447,480||18.1%||15 Dec 2019|
|2||1,356,088,150||17.5%||15 Dec 2019|
|3||330,416,190||4.26%||15 Dec 2019|
|4||265,015,300||3.42%||1 July 2018|
|5||212,742,631||2.74%||25 May 2017|
|6||210,851,274||2.72%||15 Dec 2019|
|7||188,500,000||2.43%||31 October 2016|
|8||167,758,686||2.16%||15 Dec 2019|
|9||146,877,088||1.89%||1 January 2018|
|10||126,577,691||1.63%||1 July 2019|
Approximately 4.38 billion people live in these ten countries, representing around 57% of the world's population as of July 2018.
Most densely populated countries
The tables below list the world's most densely populated countries, both in absolute terms and in comparison to their total populations.
|Rank||Country||Population||Area (km2)||Density |
(Pop. per km2)
|Rank||Country||Population||Area (km2)||Density |
(Pop. per km2)
|3||167,760,000||143,998||1,165||Rapidly growing population|
|8||51,635,256||99,538||519||Slowly growing population|
|9||23,577,488||36,193||651||Slowly declining population|
Population size fluctuates at differing rates in differing regions. Nonetheless, population growth is the long-standing trend on all inhabited continents, as well as in most individual states. During the 20th century, the global population saw its greatest increase in known history, rising from about 1.6 billion in 1900 to over 6 billion in 2000. A number of factors contributed to this increase, including the lessening of the mortality rate in many countries by improved sanitation and medical advances, and a massive increase in agricultural productivity attributed to the Green Revolution.
In 2000, the United Nations estimated that the world's population was growing at an annual rate of 1.14% (equivalent to around 75 million people), down from a peak of 88 million per year in 1989. By 2000, there were approximately ten times as many people on Earth as there had been in 1700. Globally, the population growth rate has been steadily declining from its peak of 2.19% in 1963, but growth remains high in Latin America, the Middle East, and Sub-Saharan Africa.
In 2006, the United Nations stated that the rate of population growth was visibly diminishing due to the ongoing global demographic transition. If this trend continues, the rate of growth may diminish to zero by 2050, concurrent with a world population plateau of 9.2 billion. However, this is only one of many estimates published by the UN; in 2009, UN population projections for 2050 ranged between around 8 billion and 10.5 billion. An alternative scenario is given by the statistician Jorgen Randers, who argues that traditional projections insufficiently take into account the downward impact of global urbanization on fertility. Randers' "most likely scenario" reveals a peak in the world population in the early 2040s at about 8.1 billion people, followed by decline. Adrian Raftery, a University of Washington professor of statistics and of sociology, states that "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."
Population growth by region
The following table gives estimates, in millions, of population in the past. The data for 1750 to 1900 are from the UN report "The World at Six Billion" whereas the data from 1950 to 2015 are from a UN data sheet.
Using the above figures, the change in population from 2010 to 2015 was:
- World: +420 million
- Africa: +142 million
- Asia: +223 million
- Europe: +3 million
- Latin America and Caribbean: +35 million
- Northern America: +14 million
- Oceania: +2.9 million
Long-term global population growth is difficult to predict. The United Nations and the US Census Bureau both give different estimates – according to the UN, the world population reached seven billion in late 2011, while the USCB asserted that this occurred in March 2012. The UN has issued multiple projections of future world population, based on different assumptions. From 2000 to 2005, the UN consistently revised these projections downward, until the 2006 revision, issued on 14 March 2007, revised the 2050 mid-range estimate upwards by 273 million.
Average global birth rates are declining fast, but vary greatly between developed countries (where birth rates are often at or below replacement levels) and developing countries (where birth rates typically remain high). Different ethnicities also display varying birth rates. Death rates can change rapidly due to disease epidemics, wars and other mass catastrophes, or advances in medicine.
2012 United Nations projections show a continued increase in population in the near future with a steady decline in population growth rate; the global population is expected to reach between 8.3 and 10.9 billion by 2050. 2003 UN Population Division population projections for the year 2150 range between 3.2 and 24.8 billion. One of many independent mathematical models supports the lower estimate, while a 2014 estimate forecasts between 9.3 and 12.6 billion in 2100, and continued growth thereafter. The 2019 Revision of the UN estimates gives the "medium variant" population as; nearly 8.6 billion in 2030, about 9.7 billion in 2050 and about 10.9 billion in 2100. Some analysts have questioned the sustainability of further world population growth, highlighting the growing pressures on the environment, global food supplies, and energy resources.
In 1975, Sebastian von Hoerner proposed a formula for population growth which represented hyperbolic growth with an infinite population in 2025. The hyperbolic growth of the world population observed until the 1970s was later correlated to a non-linear second order positive feedback between demographic growth and technological development. This feedback can be described as follows: technological advance → increase in the carrying capacity of land for people → demographic growth → more people → more potential inventors → acceleration of technological advance → accelerating growth of the carrying capacity → faster population growth → accelerating growth of the number of potential inventors → faster technological advance → hence, the faster growth of the Earth's carrying capacity for people, and so on. The transition from hyperbolic growth to slower rates of growth is related to the demographic transition.
According to the Russian demographer Sergey Kapitsa, the world population grew between 67,000 BC and 1965 according to the following formula:
- N is current population
- T is the current year
- C = (1.86±0.01)·1011
- T0 = 2007±1
- = 42±1
Years for world population to double
According to linear interpolation and extrapolation of UNDESA population estimates, the world population has doubled, or will double, in the years listed in the tables below (with two different starting points). During the 2nd millennium, each doubling took roughly half as long as the previous doubling, fitting the hyperbolic growth model mentioned above. However, after 2024, it is unlikely that there will be another doubling of the global population in the 21st century.
Predictions of scarcity
In his 1798 work An Essay on the Principle of Population, the British scholar Thomas Malthus incorrectly predicted that continued population growth would exhaust the global food supply by the mid-19th century. Malthus wrote the essay to refute what he considered the unattainable utopian ideas of William Godwin and Marquis de Condorcet, as presented in Political Justice and The Future Progress of the Human Mind. In 1968, Paul R. Ehrlich reprised Malthus' argument in The Population Bomb, predicting that mass global famine would occur in the 1970s and 1980s.
The predictions of Ehrlich and other neo-Malthusians were vigorously challenged by a number of economists, notably Julian Lincoln Simon, and advances in agriculture, collectively known as the Green Revolution, forestalled any potential global famine in the late 20th century. Between 1950 and 1984, as the Green Revolution transformed agriculture around the world, grain production increased by over 250%. The world population has grown by over four billion since the beginning of the Green Revolution, but food production has so far kept pace with population growth. Most scholars believe that, without the Revolution, there would be greater levels of famine and malnutrition than the UN presently documents. However, neo-Malthusians point out that fossil fuels provided the energy for the Green Revolution, in the form of natural gas-derived fertilizers, oil-derived pesticides, and hydrocarbon-fueled irrigation, and that many crops have become so genetically uniform that a crop failure in any one country could potentially have global repercussions.
In 2004, a meta-analysis of 70 quantitative studies estimating a sustainable limit to the world population generated a meta-estimate of 7.7 billion people.
In May 2008, the price of grain was pushed up severely by the increased cultivation of biofuels, the increase of world oil prices to over $140 per barrel ($880/m3), global population growth, the effects of climate change, the loss of agricultural land to residential and industrial development, and growing consumer demand in the population centres of China and India. Food riots subsequently occurred in some countries. However, oil prices then fell sharply. Resource demands are expected to ease as population growth declines, but it is unclear whether mass food wastage and rising living standards in developing countries will once again create resource shortages.
David Pimentel, professor of ecology and agriculture at Cornell University, estimates that the sustainable agricultural carrying capacity for the United States is about 200 million people; its population as of 2015 is over 300 million. In 2009, the UK government's chief scientific advisor, Professor John Beddington, warned that growing populations, falling energy reserves and food shortages would create a "perfect storm" of shortages of food, water, and energy by 2030. According to a 2009 report by the United Nations Food and Agriculture Organization (FAO), the world will have to produce 70% more food by 2050 to feed a projected extra 2.3 billion people.
The observed figures for 2007 showed an actual increase in absolute numbers of undernourished people in the world, with 923 million undernourished in 2007, versus 832 million in 1995. The 2009 FAO estimates showed an even more dramatic increase, to 1.02 billion.
A number of scientists have argued that the current global population expansion and accompanying increase in resource consumption threatens the world's ecosystem. The InterAcademy Panel Statement on Population Growth, which was ratified by 58 member national academies in 1994, states that "unprecedented" population growth aggravates many environmental problems, including rising levels of atmospheric carbon dioxide, global warming, and pollution. Indeed, some analysts claim that overpopulation's most serious impact is its effect on the environment. The situation has continued to worsen, as at the time of the 1994 IAP statement, the world population stood at 5.5 billion and lower-bound scenarios predicted a peak of 7.8 billion by 2050, a number that current estimates state will be reached in the late 2020s.
Scientists contend that human overpopulation, continued human population growth and overconsumption, particularly by the wealthy, are the primary drivers of mass species extinction. By 2050 population growth, along with profligate consumption, could result in oceans containing more plastic than fish by weight. In November 2017, a statement by 15,364 scientists from 184 countries asserted that rapid human population growth is the "primary driver behind many ecological and even societal threats." African wildlife populations are declining significantly as growing human populations encroach on protected ecosystems, such as the Serengeti. The Global Assessment Report on Biodiversity and Ecosystem Services, released by IPBES in 2019, states that human population growth is a factor in biodiversity loss.
A July 2017 study published in Environmental Research Letters argued that the most significant way individuals could mitigate their own carbon footprint is to have fewer children, followed by living without a vehicle, foregoing air travel, and adopting a plant-based diet.
Human population control is the practice of intervening to alter the rate of population growth. Historically, human population control has been implemented by limiting a region's birth rate, by voluntary contraception or by government mandate. It has been undertaken as a response to factors including high or increasing levels of poverty, environmental concerns, and religious reasons. The use of abortion in some population control strategies has caused controversy, with religious organizations such as the Roman Catholic Church explicitly opposing any intervention in the human reproductive process.
The University of Nebraska publication Green Illusions argues that population control to alleviate environmental pressures need not be coercive. It states that "Women who are educated, economically engaged, and in control of their own bodies can enjoy the freedom of bearing children at their own pace, which happens to be a rate that is appropriate for the aggregate ecological endowment of our planet." The book Fatal Misconception by Matthew Connelly similarly points to the importance of supporting the rights of women in bringing population levels down over time.
Number of humans who have ever lived
Estimates of the total number of humans who have ever lived range in the order of 100 billion. It is difficult for estimates to be better than rough approximations, as even modern population estimates are fraught with uncertainties on the order of 3% to 5%. Kapitza (1996) cites estimates ranging between 80 and 150 billion. Haub (1995) prepared another figure, updated in 2002 and 2011; the 2011 figure was approximately 107 billion. Haub characterized this figure as an estimate that required "selecting population sizes for different points from antiquity to the present and applying assumed birth rates to each period".
Robust population data only exists for the last two or three centuries. Until the late 18th century, few governments had ever performed an accurate census. In many early attempts, such as in Ancient Egypt and the Persian Empire, the focus was on counting merely a subset of the population for purposes of taxation or military service. Thus, there is a significant margin of error when estimating ancient global populations.
Another critical factor for such an estimate is the question of pre-modern infant mortality rates; these figures are very difficult to estimate for ancient times due to a lack of accurate records. Haub (1995) estimates that around 40% of those who have ever lived did not survive beyond their first birthday. Haub also stated that "life expectancy at birth probably averaged only about ten years for most of human history", which is not to be mistaken for the life expectancy after reaching adulthood. The latter equally depended on period, location and social standing, but calculations identify averages from roughly 30 years upward.
- Demographics of the world
- Birth control
- Coastal population growth
- Demographic transition
- Doomsday argument
- Family planning
- Food security
- One-child policy
- Population boom
- Population Matters, charity encouraging smaller families
- Population Reference Bureau, population demographics and annual World Population Data Sheet
- Two-child policy
- World's largest cities
- List of countries and dependencies by population
- List of urban areas by population
- List of population concern organizations
- List of countries by fertility rate
- List of countries by past and future population
- List of countries by population in 1900
- List of countries by population density
- List of countries by population growth rate
- Lists of organisms by population – for non-human global populations
- List of religious populations
- Excluding its Special Administrative Regions (SARs) of Hong Kong and Macau.
- Including Central America and the Caribbean.
- The Antarctic Treaty System limits the nature of national claims in Antarctica. Of the territorial claims in Antarctica, the Ross Dependency has the largest population.
- Figure refers to Mainland China only. It excludes Taiwan and the special administrative regions of Hong Kong and Macau.
- Figure including Crimea and Sevastopol.
- "World Development Indicators - Google Public Data Explorer". www.google.com. Retrieved 4 October 2019.
- "World Population Clock: 7.7 Billion People (2019) - Worldometers". www.worldometers.info. Retrieved 27 April 2019.
- "World Population to Hit Milestone With Birth of 7 Billionth Person". PBS NewsHour. 27 October 2011. Retrieved 11 February 2018.
- "World population hits 6 billion". 4 March 2004. Retrieved 11 February 2018.
- Jean-Noël Biraben (1980), "An Essay Concerning Mankind's Evolution". Population, Selected Papers. Vol. 4. pp. 1–13. Original paper in French:(b) Jean-Noël Biraben (1979)."Essai sur l'évolution du nombre des hommes". Population. Vol. 34 (no. 1). pp. 13–25.
- "World Population Prospects". esa.un.org. Population Division – United Nations. Retrieved 15 September 2016.
- Ortiz-Ospina, Esteban; Roser, Max (9 May 2013). "World Population Growth". Our World in Data.
- "World Population Prospects". population.un.org. Population Division –United Nations. Retrieved 26 March 2019.
- "World Population Prospects, 2012 revision (697 million births from 1985–1990)". United Nations. 2012. Archived from the original on 27 August 2014. Retrieved 11 May 2015.
- "Annual number of births – World". United Nations Population Division. 2011. Retrieved 27 March 2015.
- "World Population estimates by the US Census Bureau". USCB. Archived from the original on 11 January 2012. Retrieved 22 May 2012.
- male 29.6, female 31.1 years."CIA, The World Factbook: Field Listing: Median Age". www.cia.gov. Retrieved 13 May 2018.
- World Population 2019
- "World Population Prospects: The 2015 Revision". UN Population Division. Archived from the original on 22 December 2015.. Linked to at Download Files, where it states that the figures are for July 1 of the given year.
- "World Population Prospects: The 2010 Revision Population Database". United Nations. 15 April 2011. Retrieved 21 April 2012.
- "Antarctica". CIA World Factbook. 19 June 2014. Retrieved 18 March 2015.
- "Largest Cities in Europe".
- the compound "world population" becomes common from c. the 1930s, adapted from early 20th-century "world's population"; pre-20th century authors use "population of the world".
- "The population of the world, which Sir W. P. in 1682, stated at only 320 millions, has been estimated by some writers at about 730 millions, by others, at upwards of 900 millions; Mr. Wallace, of Edinburgh, conjectured it might amount to 1000 millions, and this number has since generally been adopted who have noticed the subject;" The Monthly Magazine 4 (July–December 1797), p. 167.
- 600 million: Simon Gray, The Happiness of States (1818), p. 356. 800 million: Gordon Hall, Samuel Newell, The Conversion of the World (1818), p. 10. 800 to 1000 million: John Redman Coxe, Considerations Respecting the Recognition of Friends in Another World (1845), p. 21 (footnote with references).
- "even recent demographic data is accurate only from 3 to 5%, although in demography traditionally more digits are indicated than those having a meaning. This is partially due to the ethical difficulty in rounding off numbers that supposedly represent real people, officially counted during a census." Sergei P Kapitza, 'The phenomenological theory of world population growth', Physics-Uspekhi 39(1) 57-71 (1996).
- Luc-Normand Tellier (2009). Urban world history: an economic and geographical perspective. p. 26. ISBN 978-2-7605-1588-8.
- Ralph Thomlinson, 1975, Demographic Problems: Controversy over population control, 2nd Ed., Dickenson Publishing Company, Ecino, CA, ISBN 0-8221-0166-1.
- Dr. Kenneth W. Harl (1998). "Population estimates of the Roman Empire". Tulane.edu. Archived from the original on 7 May 2016. Retrieved 8 December 2012.
- "Plague, Plague Information, Black Death Facts, News, Photos". National Geographic. Retrieved 3 November 2008.
- "History of Europe – Demographic and agricultural growth". Encyclopædia Britannica. 2012. Retrieved 17 December 2012.
- "Historical Estimates of World Population". Census.gov. Retrieved 12 November 2016.
- Jay, Peter (17 July 2000). "A Distant Mirror". TIME Europe. 156 (3). Archived from the original on 25 July 2008. Retrieved 9 August 2014.
- Horst R. Thieme (2003). Mathematics in population biology. p. 285. ISBN 978-0-691-09291-1.
- Graziella Caselli; Gillaume Wunsch & Jacques Vallin (2005). Demography: Analysis and Synthesis, Four Volume Set: A Treatise in Population. p. 34. ISBN 978-0-12-765660-1.
- Nishijima, Sadao (1986), "The economic and social history of Former Han", in Twitchett, Denis; Loewe, Michael, Cambridge History of China: Volume I: the Ch'in and Han Empires, 221 B.C. – A.D. 220, Cambridge: Cambridge University Press, pp 595-96.
- "Qing China's Internal Crisis: Land Shortage, Famine, Rural Poverty". Columbia University: Asia for Educators. 2009. Retrieved 9 July 2013.
- "History of Europe – Demographics". Encyclopædia Britannica. Retrieved 9 July 2013.
- "China's Population: Readings and Maps". Columbia University: East Asian Curriculum Project. Retrieved 18 December 2012.
- "The Columbian Exchange". University of North Carolina. Archived from the original on July 26, 2011. Retrieved December 18, 2012.
- Collingham, Lizzie (2006). Vindaloo: the Portuguese and the chilli pepper. Curry: A Tale of Cooks and Conquerors. Oxford: Oxford University Press. pp. 47–73. ISBN 978-0-19-988381-3.
- "Super-Sized Cassava Plants May Help Fight Hunger In Africa". Ohio State University. May 24, 2006. Archived from the original on December 8, 2013. Retrieved July 9, 2013.
- James Brabazon (2000). Albert Schweitzer: a biography. p. 242. ISBN 978-0-8156-0675-8.
- "U.S. News 08/18/97: How many people were here before Columbus? Pick a number". web.archive.org. 5 March 2008. Retrieved 9 August 2019.
- Snow, D. R (16 June 1995). "Microchronology and Demographic Evidence Relating to the Size of Pre-Columbian North American Indian Populations". Science. 268 (5217): 1601–1604. Bibcode:1995Sci...268.1601S. doi:10.1126/science.268.5217.1601. PMID 17754613.
- Arthur C. Aufderheide; Conrado Rodríguez-Martín & Odin Langsjoen (1998). The Cambridge encyclopedia of human paleopathology. p. 205. ISBN 978-0-521-55203-5.
- "The Story Of... Smallpox – and other Deadly Eurasian Germs". Public Broadcasting Service. 2005. Retrieved 24 April 2013.
- Austin Alchon, Suzanne (2003). A pest in the land: new world epidemics in a global perspective. University of New Mexico Press. p. 31. ISBN 978-0-8263-2871-7.
- "World Demographics Profile 2012". Index Mundi. Retrieved 22 May 2012.
- "By 2050, 70% of the world's population will be urban. Is that a good thing?". Fast Co. Design. 2012. Retrieved 1 May 2012.
- Population crises and cycles in history – A review by Claire Russell and W.M.S. Russell, Vicnet.net.au, archived from the original on April 5, 2011, retrieved March 26, 2015
- Buer, Mabel C. (1926). Health, Wealth and Population in the Early Days of the Industrial Revolution. London: George Routledge & Sons. p. 30. ISBN 978-0-415-38218-2.
- "The Foundling Hospital". BBC History. 5 October 2012. Retrieved 22 April 2013.
- "Modernization – Population Change". Encyclopædia Britannica. Retrieved 6 February 2013.
- Graziella Caselli; Gillaume Wunsch & Jacques Vallin (2005). Demography: Analysis and Synthesis, Four Volume Set: A Treatise in Population. p. 42. ISBN 978-0-12-765660-1.
- "Victorian Medicine – From Fluke to Theory". BBC History. 1 February 2002. Retrieved 17 February 2013.
- "A portrait of Britain in 2031". The Independent. 24 October 2007. Retrieved 17 February 2013.
- "UK population breaks through 60m". BBC News. 24 August 2006. Retrieved 14 April 2012.
- "US population through history". About.com. Retrieved 14 April 2012.
- Jay Winter, Emmanuel Sivan (2000). War and Remembrance in the Twentieth Century. Cambridge University Press. p. 64. ISBN 978-0521794367.
- Mark Harrison (2002). Accounting for War: Soviet Production, Employment, and the Defence Burden, 1940–1945. p. 167. ISBN 978-0-521-89424-1.
- "Vladimir Putin vows to reverse Russian population decline". The Daily Telegraph. 13 February 2012. Retrieved 13 April 2012.
- "Russia's Population Decline Said To Have 'Stopped'". Radio Free Europe. 27 May 2013. Retrieved 15 June 2013.
- Schran, Peter (1978). "China's demographic evolution 1850–1953 reconsidered". The China Quarterly (75): 639–646. JSTOR 652987.
- "Reintegrating India with the World Economy" (PDF). Peterson Institute for International Economics. 2003. Retrieved 8 November 2012.
- "The World Factbook — Central Intelligence Agency". www.cia.gov. Retrieved 8 January 2017.
- "Java (island, Indonesia)". Encyclopædia Britannica. Retrieved 7 July 2013.
- Jorge Durand (March 2004). "From Traitors to Heroes: 100 Years of Mexican Migration Policies". University of Guadalajara. Retrieved 16 July 2013.
- "Population and Housing Census: Mexico 2010" (PDF). University of Minnesota. 3 March 2011. Retrieved 16 July 2013.
- Gunnar Heinsohn (7 January 2008). "Kenya's Violence: Exploding population". The New York Times. Retrieved 7 July 2013.
- "The World at Six Billion: Introduction" (PDF). United Nations. 1999. Archived from the original (PDF) on 5 February 2016. Retrieved 14 July 2013.
- "U.S. Census Bureau – World POPClock Projection". July 2013. The number on this page is automatically updated daily.
- "Population seven billion: UN sets out challenges". BBC News. 26 October 2011. Retrieved 27 October 2011.
- Coleman, Jasmine (31 October 2011). "World's 'seven billionth baby' is born". The Guardian. London. Retrieved 31 October 2011.
- "7 billion people is a 'serious challenge". UPI. 31 October 2011. Retrieved 9 November 2011.
- "Ch. 5: Population Size and Composition" (PDF). World Population Prospects, the 2000 Revision. Vol.III. United Nations Population Division. p. 171. Retrieved 3 July 2010.
- "Executive Summary" (PDF). World Population Prospects: The 2002 Revision Volume III: Analytical Report. 2002. Retrieved 3 July 2010.
- "World Population to 2300" (PDF). New York: United Nations Department of Economic and Social Affairs: Population Division. 2004. pp. 3, 14. Retrieved 3 July 2010.
- "World Population: 1950–2050". United States Census Bureau. June 2010. Retrieved 3 July 2010.
- "2009 World Population Data Sheet" (PDF). Washington, DC: Population Reference Bureau. 2009. Retrieved 3 July 2010.
- "Key Findings" (PDF). Long-Range Population Projections. Proceedings of the United Nations Technical Working Group on Long-Range Population Projections. New York: United Nations: Department of Economic and Social Affairs. 2003. Retrieved 3 July 2010.
- "Total fertility estimates, 1950–2010". UN Population Division. April 2011. Retrieved 14 June 2012.
- "World Population Prospects, the 2008 Revision – Frequently Asked Questions". Population Division of the Department of Economic and Social Affairs of the United Nations Secretariat. 10 November 2010. Retrieved 26 March 2015.
- "World Health Statistics 2016: Monitoring health for the SDGs Annex B: tables of health statistics by country, WHO region and globally" (PDF). World Health Organization. 2016. p. 110. Retrieved 3 August 2018.
- "World Demographics Profile 2011". Index Mundi. Retrieved 18 November 2011.
- "Sex-ratio imbalance in Asia: Trends, consequences and policy responses" (PDF). UNFPA. 2007. Retrieved 20 May 2012.
- "World Demographics Profile 2014". Index Mundi. Retrieved 4 October 2014.
- Janneh, Abdoulie (April 2012). "General debate on national experience in population matters: adolescents and youth" (PDF). United Nations Economic Commission for Africa. Retrieved 19 February 2014.
- "Global weight gain more damaging than rising numbers". BBC. 18 June 2012. Retrieved 12 February 2013.
- "World". CIA World Factbook. 2015. Retrieved 17 January 2015.
- "What It Will Take to 'Graduate' 1.2 Billion People Out of Extreme Poverty". The Huffington Post. 4 April 2012. Retrieved 26 April 2012.
- Food and Agriculture Organization of the United Nations, The State of Food Insecurity in the World. WorldHunger.org. 2012. Retrieved 26 April 2012.
- "Statistics". Internet World Stats. 30 June 2014. Retrieved 5 March 2015.
- "World’s Most Typical Person: Han Chinese Man". Wall Street Journal. 4 March 2011. Retrieved 18 November 2011.
- Religions by adherents. Adherents.com. 2005 data. Retrieved 19 December 2011.
- "Chinese Official Population Clock (updated daily, in Chinese)". National Bureau of Statistics of China. Retrieved 23 August 2016.
- "Official population clock".
- "United States Official Population Clock (updated daily)". USCB.
- "Official annual projection". Retrieved 1 July 2018.
- "Pakistan Bureau of Statistics - Census".
- "Official population clock". IBGE.gov.br.
- "Population, total". World Bank. 2014. Retrieved 21 March 2015.
- "Official population clock". BBS.gov.bd. Archived from the original on September 4, 2011. Retrieved October 4, 2014.
- "Official estimate (including Crimea and Sevastopol)". GKS.ru. Retrieved 1 July 2018.
- "Official annual projection". Official Mexico Statistics Bureau. Retrieved 1 July 2019.
- Demetriou, Danielle (17 April 2013). "Japan's population suffers biggest fall in history". Daily Telegraph. London. Retrieved 22 July 2013.
- "The limits of a Green Revolution?". BBC News. 29 March 2007. Retrieved 1 August 2010.
- "The Real Green Revolution". Energybulletin.net. Archived from the original on 22 April 2008. Retrieved 1 August 2010.
- "World Population to 2300" (PDF). United Nations Department of Economic and Social Affairs. 2004. Retrieved 16 June 2013.
- "International Programs". USCB. 7 January 2009. Retrieved 16 December 2012.
- Ron Nielsen (2006). The Little Green Handbook. New York: Picador. ISBN 978-0-312-42581-4.
- "2006 report highlights" (PDF). United Nations. Retrieved 1 August 2010.
- "UN population estimates and projections, database query, August 2009". United Nations. 11 March 2009. Retrieved 1 August 2010.
- Randers, Jorgen (2012). 2052: A Global Forecast for the Next Forty Years. Vermont: Chelsea Green Publishing. p. 62.
- World population to keep growing this century, hit 11 billion by 2100. UWToday. 18 September 2014
- "World Population Prospects: The 2008 Revision" (PDF). Population Division of the Department of Economic and Social Affairs of the United Nations Secretariat. June 2009. Retrieved 20 June 2013.
- "The World at Six Billion". United Nations. 12 October 1999. Retrieved 1 August 2010.
- "Population Growth over Human History". University of Michigan. January 4, 2006. Archived from the original on July 24, 2011. Retrieved March 9, 2013.
- Figures include the former Soviet countries in Europe. Caselli, Graziella; Gillaume Wunsch; Jacques Vallin (20 December 2005). Demography: Analysis and Synthesis, Four Volume Set: A Treatise in Population. Academic Press. p. 42. ISBN 978-0-12-765660-1.
- "UN report – 2004 data" (PDF). Archived from the original (PDF) on 5 February 2016. Retrieved 1 August 2010.
- "World Population Prospects The 2015 Revision" (PDF).
- "The World at Six Billion". UN Population Division. Archived from the original on 5 March 2016., Table 2
- Fewer than 15,000 individuals, according to the Toba catastrophe theory, though this theory has been criticized by some scientists. See: "Toba super-volcano catastrophe idea "dismissed"". BBC News. 30 April 2013. Retrieved 21 March 2015.
- An approximation based on figures from different sources as listed at the US Census Bureau's Historical Estimates of World Population; see also *Kremer, Michael (1993). "Population Growth and Technological Change: One Million B.C. to 1990". The Quarterly Journal of Economics. 108 (3): 681–716. doi:10.2307/2118405. JSTOR 2118405.
- An approximation based on figures from different sources as listed at the US Census Bureau's Total Midyear Population for the World: 1950-2050
- "Notes on the World POPClock and World Vital Events". US Census Bureau. Retrieved 12 February 2013.
- "World Population Prospects, the 2012 Revision – "Low variant" and "High variant" values". UN. 2012. Retrieved 15 June 2013.
- "World population projected to reach 9.6 billion by 2050 – UN report". UN News Centre. 14 June 2013. Retrieved 16 June 2013.
- "A model predicts that the world's populations will stop growing in 2050". ScienceDaily.com. 4 April 2013. Retrieved 3 June 2013.
- Carrington, Damien (18 September 2014). "World population to hit 12bn in 2100 – with 70% chance of continuous rise". The Guardian. Retrieved 21 September 2014.
- 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. (14 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.
- World Population Prospects 2019: Highlights
- Peter P. Rogers; Kazi F. Jalal & John A. Boyd (2008). An Introduction To Sustainable Development. p. 53. ISBN 9781849770477.
- "Overpopulation's Real Victim Will Be the Environment". TIME. 26 October 2011. Retrieved 18 February 2013.
- Zehner, Ozzie (2012). Green Illusions. Lincoln and London: University of Nebraska Press. pp. 187–331.
- "World Population Prospects: The 2019 Revision" (XLS). Population Division of the Department of Economic and Social Affairs of the United Nations Secretariat. June 2019. Retrieved 8 July 2019.
- "World Population – Total Midyear Population for the World: 1950–2050". Census.gov. July 2015. Retrieved 7 March 2016.
- Sebastien von Hoerner (1975). "Population Explosion and Interstellar Expansion". Journal of the British Interplanetary Society (28): 691–712.
- Introduction to Social Macrodynamics. Andrey Korotayev et al. For a rigorous mathematical analysis of this issue, see "A Compact Mathematical Model of the World System Economic and Demographic Growth, 1 CE – 1973 CE".
- Kapitsa, Sergei P. (1996). "The phenomenological theory of world population growth". Physics-Uspekhi. 39 (1): 57–71. Bibcode:1996PhyU...39...57K. doi:10.1070/pu1996v039n01abeh000127. Archived from the original on 11 May 2009. Retrieved 26 July 2013.
- Lutz, Wolfgang; Sanderson, Warren; Scherbov, Sergei (19 June 1997). "Doubling of world population unlikely" (PDF). Nature. 387 (6635): 803–805. Bibcode:1997Natur.387..803L. doi:10.1038/42935. PMID 9194559.
- "World faces 'perfect storm' of problems by 2030, chief scientist to warn". The Guardian. 18 March 2009. Retrieved 18 February 2013.
- Jowit, Juliette (23 October 2011). "Paul Ehrlich, a prophet of global population doom who is gloomier than ever". The Guardian. London. Retrieved 22 July 2013.
- Kindall, Henery W & Pimentel, David (May 1994). "Constraints on the Expansion of the Global Food Supply". Ambio. 23 (3).
- "The limits of a Green Revolution?". BBC News. 29 March 2007. Retrieved 18 February 2013.
- "Host Plant Resistance and Conservation of Genetic Diversity". Radcliffe's IPM World Textbook. University of Minnesota. March 2013. Retrieved 20 July 2013.
- 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.
- "The global grain bubble". Christian Science Monitor. 18 January 2008. Retrieved 18 February 2013.
- James Randerson, science correspondent (7 March 2008). "Food crisis will take hold before climate change, warns chief scientist". The Guardian. London. Retrieved 18 February 2013.
- John Vidal, environment editor (3 November 2007). "Global food crisis looms as climate change and fuel shortages bite". The Guardian. London. Retrieved 18 February 2013.CS1 maint: extra text: authors list (link)
- Walsoft (22 February 2008). "Experts: Global Food Shortages Could 'Continue for Decades'". Marketoracle.co.uk. Retrieved 18 February 2013.
- Moya K. Mason. "Has Urbanization Caused a Loss to Agricultural Land?". Moyak.com. Retrieved 9 July 2013.
- Walt, Vivienne (27 February 2008). "The World's Growing Food-Price Crisis". Time. Retrieved 18 February 2013.
- "The cost of food: Facts and figures". BBC. 16 October 2008. Retrieved 18 February 2013.
- Julian Borger (26 February 2008). "Feed the world? We are fighting a losing battle, UN admits". The Guardian. London. Retrieved 18 February 2013.
- Buchanan, Emily (22 April 2008). "Assessing the global food crisis". BBC News. Retrieved 6 April 2010.
- "Half of all food 'wasted' report claims". BBC. 10 January 2013. Retrieved 10 January 2013.
- "Oil shock could push world food prices higher". CNN Money. 3 March 2011. Retrieved 18 February 2013.
- P. Crabbè (2000). Implementing ecological integrity: restoring regional and global environmental and human health. North Atlantic Treaty Organization Scientific Affairs Division/Springer. p. 411. ISBN 978-0-7923-6351-4.
- "Global crisis 'to strike by 2030". BBC News. 19 March 2009. Retrieved 18 February 2013.
- "Global food production will have to increase 70% for additional 2.3 billion people by 2050". Finfacts.com. 24 September 2009. Retrieved 18 February 2013.
- "The State of Food Insecurity in the World, 2008: High food prices and food security – threats and opportunities". UN Food and Agriculture Organization – Economic and Social Development Department. 2008. p. 2. Retrieved 8 December 2012.
- "One sixth of humanity undernourished – more than ever before". Food and Agriculture Organization of the United Nations. 2009. Retrieved 8 December 2012.
- "Ecological Debt Day". Archived from the original on December 17, 2008. Retrieved February 18, 2013.
- "Planetary Boundaries: Specials". Nature. 23 September 2009. Retrieved 18 February 2013.
- "IAP (login required)". InterAcademies.net. Archived from the original on 10 February 2010. Retrieved 18 February 2013.
- 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. Retrieved 15 December 2016.
The overarching driver of species extinction is human population growth and increasing per capita consumption.
- 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.
- Sutter, John D. (12 December 2016). "How to stop the sixth mass extinction". CNN. Retrieved 19 December 2016.
- 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.
- 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". BioScience. 67 (12): 1026–1028. doi:10.1093/biosci/bix125.
- Cockburn, Harry (29 March 2019). "Population explosion fuelling rapid reduction of wildlife on African savannah, study shows". The Independent. Retrieved 1 April 2019.
- Watts, Jonathan (6 May 2019). "Human society under urgent threat from loss of Earth's natural life". The Guardian. Retrieved 23 June 2019.
- Perkins, Sid (11 July 2017). "The best way to reduce your carbon footprint is one the government isn't telling you about". Science. Retrieved 9 December 2017.
- Some population control programs, such as China's one-child policy, entail the use of forced late-term abortions, sparking domestic anger and international condemnation: "China one-child policy leads to forced abortions, mothers' deaths". Los Angeles Times. 15 June 2012. Retrieved 29 August 2012.
- "Fighting poverty to build peace". Vatican. 1 January 2009. Retrieved 24 October 2011.
- Zehmer, Ozzie (2012). Green lllusions. Lincoln and London: University of Nebraska. p. 188.
- Connelly, Matthew (2008). Fatal Misconception: The Struggle to Control World Population. ISBN 9780674029835.
- Sergei P Kapitza, 'The phenomenological theory of world population growth', Physics-Uspekhi 39(1) 57-71 (1996), citing K. M. Weiss, Human Biology 56637 (1984) and N. Keyfitz, Applied Mathematical Demography (New York: Wiley, 1977).
- Curtin, Ciara (1 March 2007). "Fact or Fiction?: Living People Outnumber the Dead". Scientific American. Scientific American, Inc. (published September 2007). 297 (3): 126. Bibcode:2007SciAm.297c.126C. doi:10.1038/scientificamerican0907-126. PMID 17784634. Retrieved 4 August 2008. Note: text of paper publication slightly different from text of on-line publication
- Haub, Carl (November–December 2002). "How Many People Have Ever Lived on Earth?" (PDF). Population Today. Population Reference Bureau. 30 (8): 3–4. Retrieved 4 August 2008.
- Haub, Carl (October 2011). "How Many People Have Ever Lived on Earth?". Population Reference Bureau. Retrieved 29 April 2013.
- Kuhrt, A. (1995). The Ancient Near East, c. 3000–330 BCE. Vol. 2. London: Routledge. p. 695.
|Wikimedia Commons has media related to World population statistics.|
- Cohen, Joel E. (1995). How Many People Can The Earth Support?. New York: W. W. Norton. ISBN 978-0-393-31495-3.
- "World Population Prospects, the 2012 Revision". United Nations Population Division. Retrieved 19 May 2014.
- "World Population Prospects, the 2010 Revision". United Nations Population Division. Retrieved 25 June 2013.
- "World Population History Graph" World population graph 10000 BC - AD 1950.
- "Symptoms of The Global Demographic Decline". Demographia.ru. Retrieved 25 June 2013.
- World Factbook 2012. US Central Intelligence Agency (CIA). Retrieved 6 November 2012.
- "The World in Balance" (transcript). Two-part PBS Nova on world population. 20 April 2004. Retrieved 19 July 2013.
- "The Environmental Politics of Population and Overpopulation". University of California, Berkeley. 2012. Retrieved 19 July 2013.
- "Global population: Faces of the future". The Economist. 22 June 2013. Retrieved 25 June 2013.
- "Creating new life – and other ways to feed the world". BBC. 23 July 2013. Retrieved 23 July 2013.
- World Population Growth (Oct 2016), Esteban Ortiz-Ospina and Max Roser, OurWorldInData.org
- Optimum Population Trust
- The Day of 6 Billion and 7 Billion – Official homepages maintained by UNFPA
- Population Reference Bureau – News and issues related to population
- Berlin Institute for Population and Development
Statistics and maps
- HiveGroup.com – World population statistics presented in a treemap interface
- PopulationLabs.com – World population map and graph
- PopulationData.net – Information and maps about populations around the world
- Win.tue.nl – World countries mapped by population size
- World-statistics.org – World statistics including population and projections