Product Code Database
In world demographics, the world population is the total number of currently alive. It was estimated by the United Nations to have exceeded eight billion in mid-November 2022. It took around 300,000 years of human prehistory and human history for the human population to reach a billion and only 218 more years to reach 8 billion.
The human population has experienced continuous growth following the Great Famine of 1315–1317 and the end of the Black Death in 1350, when it was nearly 370,000,000.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. The highest global population growth rates, with increases of over 1.8% per year, occurred between 1955 and 1975, peaking at 2.1% between 1965 and 1970. The growth rate declined to 1.1% between 2015 and 2020 and is projected to decline further in the 21st century. The global population is still increasing, but there is significant uncertainty about its long-term trajectory due to changing fertility and Mortality rate rates. The UN Department of Economics and Social Affairs projects between 9 and 10 billion people by 2050 and gives an 80% confidence interval of 10–12 billion by the end of the 21st century, with a growth rate by then of zero. Other Demography predict that the human population will begin to decline in the second half of the 21st century.
The total number of births globally is currently (2015–2020) 140 million/year, which is projected to peak during the period 2040–2045 at 141 million/year and then decline slowly to 126 million/year by 2100. The total number of deaths is currently 57 million/year and is projected to grow steadily to 121 million/year by 2100.
The median median age of human beings is 31 years.
It is difficult for estimates to be better than rough approximations, as even current population estimates are fraught with uncertainties from 3% to 5%.
Agriculture provided a steady food supply that could be stored for a year or longer in order to minimize the risk of famine. Farm production could be expanded by systematic human exertion. The new technology of farming meant that the food supply was proportional to the number of workers who could plant and harvest the crops. Every new pair of hands meant more food for the community, so children were valued in agricultural societies. Later, additional workers found useful work in building irrigation canals and systems that provided a stable water supply for crops, especially in Egypt, Mesopotamia, India, China, Peru and Mexico. The population could now grow because new people paid their own way. (It would take many centuries before the arable land supply became a limiting factor.) However, death rates were high, especially for infants and children, so even with high birth rates growth was slow. The same amount of land could support either 1,000 hunters or 100,000 farmers, and it is easy to see which side ultimately would win a fight for the land. Farmers gathered in permanent villages, and through a process of warfare consolidated into much larger states, including those in China, India, Egypt and Mesopotamia. From 300 to 1400 AD large agricultural states also existed throughout the eastern United States, called the "Hopewell tradition" and "Mississippian cultures". They are most famous as Mound Builders, but their culture collapsed (for unknown reasons) by 1500. The natives encountered by the English and French were nomadic hunters who supplemented their meat diet with cultivated vegetables.Fekri A. Hassan, "Population dynamics" in Companion Encyclopedia of Archaeology (Routledge, 2002), pp. 672–713.Mark Nathan Cohen, The Food Crisis in Prehistory: Overpopulation and the Origins of Agriculture (Yale University Press, 1977).
The Plague of 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. From 1340 to 1400, the world's population fell from an estimated 443 million to 350–375 million, with the Indian subcontinent suffering the most tremendous loss and Europe suffering the Black Death pandemic; it took 200 years for European 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 Empire invasions, famine, and plague.
Starting in AD 2, the Han dynasty of ancient China kept consistent family registers to properly assess the poll taxes and labor service duties of each household.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. 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. From 200 to 400, the world population fell from an estimated 257 million to 206 million, with China suffering the greatest loss. 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.
Population growth in the Western world 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.
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 billion people. Java, an island in Indonesia, had about 5 million inhabitants in 1815; it had a population of over 139 million in 2020. 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.
| + World population milestones in billions (Worldometers estimates) |
The UN 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, it took 14 years for the global population to reach four billion in 1974, 13 years to reach five billion in 1987, 12 years to reach six billion in 1999 and, according to the United States Census Bureau, 13 years to reach seven billion in March 2012. The number on this page is automatically updated daily. The United Nations, however, estimated that the world population reached seven billion in October 2011.
According to the UN, the global population reached eight billion in November 2022, but because the growth rate is slowing, it will take another 15 years to reach around 9 billion by 2037 and 20 years to reach 10 billion by 2057. Alternative scenarios for 2050 range from a low of 7.4 billion to a high of more than 10.6 billion.*
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 Seven Billion" to be 31 October 2011. The United Nations marked the birth of the Vinice Mabansag on 15 November 2022. "World population to reach 8 billion this year, as growth rate slows" , UN News, 11 July 2022.
According to the World Health Organization, the global average life expectancy is 73.3 years as of 2020, with women living an average of 75.9 years and men approximately 70.8 years. In 2010, the global fertility rate was estimated at 2.44 children per woman. In June 2012, British researchers calculated the total weight of Earth's human population as approximately , with the average person weighing around .
The IMF estimated nominal 2021 gross world product at US$94.94 trillion, giving an annual global per capita figure of around US$12,290. Around 9.3% of the world population live in extreme poverty, subsisting on less than US$1.9 per day; around 8.9% are Malnutrition. Food and Agriculture Organization of the United Nations, The State of Food Insecurity in the World . WorldHunger.org. 2012. Retrieved 26 April 2012. 87% of the world's over-15s are considered literacy rate. As of January 2024, there were about 5 billion global Internet users, constituting 66% 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 languages are English language (1.132B), Mandarin Chinese (1.117B), Hindi (615M), Spanish language (534M) and French language (280M). More than three billion people speak an Indo-European language, which is the largest language family by number of speakers. Standard Arabic is a language with no native speakers, but the total number of speakers is estimated at 274 million people.
The largest religious categories in the world as of 2020 are estimated as follows: Christianity (31%), Islam (25%), Irreligion (16%) and Hinduism (15%).
However, this rapid growth did not last. During the period 2000–2005, the United Nations estimates that the world's population was growing at an annual rate of 1.3% (equivalent to around 80 million people), down from a peak of 2.1% during the period 1965–1970. Globally, although the population growth rate has been steadily declining from its peak in 1968, growth still remains high in Sub-Saharan Africa.
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In fact, during the 2010s, Japan and some countries in Europe began to reduce in population, due to sub-replacement fertility rates.
In 2019, the United Nations reported that the rate of population growth continues to decline due to the ongoing global demographic transition. If this trend continues, the rate of growth may diminish to zero by 2100, concurrent with a world population plateau of 10.9 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." World population to keep growing this century, hit 11 billion by 2100 . UWToday. 18 September 2014
Using the above figures, the change in population from 2010 to 2015 was:
Complicating the UN's and others' attempts to project future populations is the fact that average global , as well as , are declining rapidly, as the nations of the world progress through the stages of the demographic transition, but both vary greatly between developed countries (where birth rates and mortality rates are often low) and developing countries (where birth and mortality rates typically remain high). Different ethnicities also display varying birth rates. Birth rate and mortality rates can change rapidly due to disease epidemics, wars and other mass catastrophes, or Life extension and public health.
The UN's first report in 1951 showed that during the period 1950–55 the Birth rate was 36.9/1,000 population and the Mortality rate was 19.1/1,000. By the period 2015–20, both numbers had dropped significantly to 18.5/1,000 for the crude birth rate and 7.5/1,000 for the crude death rate. UN projections for 2100 show a further decline in the crude birth rate to 11.6/1,000 and an increase in the crude death rate to 11.2/1,000.
The total number of births globally is currently (2015–20) 140 million/year, is projected to peak during the period 2040–45 at 141 million/year and thereafter decline slowly to 126 million/year by 2100. The total number of deaths is currently 57 million/year and is projected to grow steadily to 121 million/year by 2100.
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. In December 2019, the German Foundation for World Population projected that the global population will reach 8 billion by 2023 as it increases by 156 every minute. In a modeled future projection by the Institute for Health Metrics and Evaluation, the global population was projected to peak in 2064 at 9.73 billion people and decline to 8.79 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.
Some scholars have argued that a form of "cultural selection" may be occurring due to significant differences in fertility rates between cultures, and it can therefore be expected that fertility rates and rates of population growth may rise again in the future. An example is certain religious groups that have a higher birth rate that is not accounted for by differences in income. In his book Shall the Religious Inherit the Earth?, Eric Kaufmann argues that demographic trends point to religious fundamentalists greatly increasing as a share of the population over the next century. From the perspective of evolutionary psychology, it is expected that selection pressure should occur for whatever psychological or cultural traits maximize fertility. Can we be sure the world's population will stop rising?, BBC News, 13 October 2012
According to the Russian demographer Sergey Kapitsa, the world population grew between 67,000 BC and 1965 according to the following formula:
Robust population data only exist 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.Kuhrt, A. (1995). The Ancient Near East, c. 3000–330 BCE. Vol. 2. London: Routledge. p. 695. Thus, there is a significant margin of error when estimating ancient global populations.
Pre-modern infant mortality rates are another critical factor for such an estimate; these rates 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.
The National Institute of Corrections estimates that the number of people who have ever lived will rise to 121 billion by 2050, 4 billion more than their 2021 estimate.
Scientists generally acknowledge that at least one significant factor contributing to population growth (or overpopulation) is that as agriculture advances in creating more food, the population consequently increases—the Neolithic Revolution and Green Revolution often specifically provided as examples of such agricultural breakthroughs.Gilland, Bernard (2006). "Population, nutrition and agriculture". Population and Environment, 28(1), 1.Bocquet-Appel, Jean-Pierre (2011). "When the world's population took off: the springboard of the Neolithic Demographic Transition". Science, 333(6042), 560–561." What Causes Overpopulation?" Euroscientist. Euroscience: "When agriculture advances, and it becomes easier to feed the population, it continues to grow."" The Development of Agriculture". National Geographic. 2022. Furthermore, certain scientific studies do lend evidence to food availability in particular being the dominant factor within a more recent timeframe.Cohen, Joel E. (1995). Population growth and earth's human carrying capacity. Science, 269(5222), 341–346.Fanta, V., Šálek, M., Zouhar, J., Sklenicka, P., & Storch, D. (2018). Equilibrium dynamics of European pre-industrial populations: the evidence of carrying capacity in human agricultural societies. Proceedings of the Royal Society B: Biological Sciences, 285(1871), 20172500. Other studies take it as a basic model from which to make broad population conjectures. The idea became taboo following the United Nations' 1994 International Conference on Population and Development, where framing human population growth as negatively impacting the natural environment became regarded as "anti-human".Henderson, Kirsten, & Loreau, Michel (2019). "An ecological theory of changing human population dynamics". People and Nature, 1(1), 32.
Most human populations throughout history validate this theory, as does the overall current global population. Populations of fluctuate in accordance with the amount of available food. The world human population began consistently and sharply to rise, and continues to do so, after sedentary agricultural lifestyles became common due to the Neolithic Revolution and its increased food supply.GJ Armelagos, AH Goodman, KH Jacobs Population and environment – 1991 link.springer.com This was, subsequent to the Green Revolution starting in the 1940s, followed by even more severely accelerated population growth. Often, wealthier countries send their surplus food resources to the aid of starving communities; however, some proponents of this theory argue that this seemingly beneficial strategy only results in further harm to those communities in the long run. Anthropologist Peter Farb, for example, has commented on the paradox that "intensification of production to feed an increased population leads to a still greater increase in population."Farb, Peter: 1978, Humankind. Boston, Houghton Mifflin. Environmental writer Daniel Quinn has also focused on this phenomenon, which he calls the "food race", coining a term he felt was comparable, in terms of both escalation and potential catastrophe, to the nuclear arms race.
Criticism of this theory can come from multiple angles, for example by demonstrating that human population is not solely an effect of food availability, but that the situation is more complex. For instance, other relevant factors that can increase or limit human population include access to birth control, fresh water availability, arable land availability, energy consumed per person, heat removal, forest products, and various nonrenewable resources like fertilizers.Van Den Bergh, Jeroen, & Rietveld, Piet (2004). "Reconsidering the limits to world population: meta-analysis and meta-prediction". BioScience, 54(3), 195–204. Another criticism is that, in the modern era, birth rates are lowest in the , 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.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. 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, according to Hopfenberg and Pimentel's 2001 research, "it is through exports from food-rich to food-poor areas... that the population growth in these food-poor areas is further fueled. Their study thus suggests that human population growth is an exacerbating feedback loop in which food availability creates a growing population, which then causes the misimpression that food production must be consequently expanded even further.Salmony, Steven E. (2006). "The Human Population: Accepting Species Limits". Environmental Health Perspectives, 114(1), A 17. .
Regardless of criticisms against the theory that population is a function of food availability, the human population is, on the global scale, undeniably increasing,Daniel Quinn (1996). The Story of B, pp. 304–305, Random House Publishing Group, . 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 globalization with food moving across national borders from areas of abundance to areas of scarcity. Hopfenberg and Pimentel's 2001 findings support both this and Daniel Quinn's direct accusation, in the early 2010s, that "First World farmers are fueling the Third World population explosion".Quinn, Daniel: "The Question (ID Number 122)". Retrieved October 2014 from .
Organizations
Statistics and maps
Population clocks
Projected figures vary depending on underlying statistical assumptions and the variables used in projection calculations, especially the fertility and Mortality rate variables. 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.
Global demographics
[[File:Expectancy of life.svg|thumb|upright=1.4|
2015 map showing average life expectancy by country in years. In 2015, the World Health Organization estimated the average global life expectancy as 71.4 years.]]
As of 2020, the global sex ratio is approximately 1.01 males to 1 female. Approximately 24.7% of the global population is aged under 15, while 65.2% is aged 15–64 and 10.1% is aged 65 or over. The median age of the world's population is estimated to be 31 years in 2020, and is expected to rise to 37.9 years by 2050.
Population by region
Six of the Earth's seven are permanently inhabited on a large scale. Asia is the most populous continent, with its 4.64 billion inhabitants accounting for 60% of the world population. The world's two most populated countries, India and China, together constitute about 36% of the world's population. Africa is the second most populated continent, with around 1.34 billion people, or 17% of the world's population. Europe's 747 million people make up 10% of the world's population as of 2020,while the Latin American and Caribbean regions are home to around 653 million (8%). Northern America, primarily consisting of the United States and Canada, has a population of around 368 million (5%), and Oceania, the least populated region, has about 42 million inhabitants (0.5%). Antarctica only has a very small, fluctuating population of about 1200 people based mainly in polar science stations.
+ Population by region (2020 estimates) Asia 4,641 1,439,090,595 13,515,000 Tokyo
(37,400,000 Greater Tokyo Area)Africa 1,340 211,401,000 9,500,000 Cairo
(20,076,000 Greater Cairo)Europe 747 146,171,000 , approx. European Russia 13,200,000 Moscow
(20,004,000 Moscow metropolitan area)Latin America 653 214,103,000 12,252,000 São Paulo City
(21,650,000 São Paulo Metro Area)Northern AmericaExcludes Mexico, Central America and the Caribbean, which are included here under Latin America. 368 332,909,000 8,804,000 New York City
(23,582,649 New York metropolitan area)Oceania 42 25,917,000 5,367,000 Sydney Antarctica ~0 0.004 N/AThe Antarctic Treaty System limits the nature of national claims in Antarctica. Of the territorial claims in Antarctica, the Ross Dependency has the largest population. 1,258 McMurdo Station
Largest populations by country
Ten most populous countries
+ World population 1,416 1,528 356 295 245 228 263 186 149 148 8,501 Notes:
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, as of November 2022. All areas and populations are from The World Factbook, unless otherwise noted.
+ 10 most densely populated countries (with population above 5 million) 8,235 1,116 Has limited international recognition as a country. Area for the purposes of these calculations is that claimed, not controlled, by the State of Palestine.| 5,223,000 ||6,025 | 867
655 520 509 500 456 429 423
Fluctuation
Population size fluctuates at differing rates in differing regions. Nonetheless, population growth has been 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 as the whole world entered the early phases of what has come to be called the "demographic transition". Some of the key factors contributing to this increase included 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. By 2000, there were approximately ten times as many people on Earth as there had been in 1700.
Annual population growth
+Global annual population growth
!rowspan=2 Year
!rowspan=2 Population
!colspan=2 Yearly growth
!rowspan=2 Density
(pop/km2)
Population growth by region
The table below shows historical and predicted regional population figures in millions. The availability of historical population figures varies by region.
+World historical and predicted populations (in millions)Figures include the former Soviet countries in Europe. +World historical and predicted populations by percentage distribution
Past population
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" Table 2 whereas the data from 1950 to 2015 are from a UN data sheet.. Linked to at Download Files, where it states that the figures are for 1 July of the given year.
Projections
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. Since 1951, 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.
+ UN (medium variant – 2019 revision) and US Census Bureau (June 2015) estimates +UN 2024 estimates and medium variant projections (in millions)
! Year
! World
! Asia
! Africa
! Europe
! Latin America/Caribbean
! Northern America
! Oceania
Mathematical approximations
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. 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". . The transition from hyperbolic growth to slower rates of growth is related to the demographic transition.
where
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.
+ Starting at 500 million
! Population
(in billions)
! colspan=216 + Starting at 375 million
! Population
(in billions)
! colspan=212
Number of humans who have ever lived
The total number of humans who have ever lived is estimated to be approximately 100 billion. Such estimates can only be rough approximations, as even modern population estimates are subject to uncertainty of around 3% to 5%."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). Kapitsa (1996) cites estimates ranging between 80 and 150 billion.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). The PRB puts the figure at 117 billion as of 2020, estimating that the current world population is 6.7% of all the humans who have lived since 190,000 BCE. Haub (1995) prepared another figure, updated in 2002 and 2011; the 2011 figure was approximately 107 billion. Note: text of paper publication slightly different from text of on-line publication. 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".
Human population as a function of food availability
Individuals from a wide range of academic fields and political backgrounds have proposed that, like all other animal populations, any human population (and, by extension, the world population) predictably grows and shrinks according to available food supply, growing during an abundance of food and shrinking in times of scarcity.Bystroff, Christopher (2021). "Footprints to singularity: A global population model explains late 20th century slow-down and predicts peak within ten years". PLoS ONE 16(5): e0247214. This idea may run counter to the popular thinking that, as population grows, food supply must also be increased to support the growing population; instead, the claim here is that growing population is the result of a growing food supply. Notable proponents of this notion include: agronomist and insect ecologist David Pimentel,Hopfenberg, Russell and Pimentel, David, " Human Population Numbers as a Function of Food Supply", Environment, Development and Sustainability, vol. 3, no. 1, March 2001, pp. 1–15 behavioral scientist Russell Hopfenberg (the former two publishing a study on the topic in 2001), anthropologist and activist Virginia Abernethy,Abernathy, Virginia, Population Politics ecologist Garrett Hardin, science writer and anthropologist Peter Farb, journalist Richard Manning, environmental biologist Alan D. Thornhill, Food Production & Population Growth, video with Daniel Quinn and Alan Thornhill cultural critic and writer Daniel Quinn,Quinn, Daniel, Ishmael Bantam/Turner, 1995, and anarcho-primitivist John Zerzan.
See also
Explanatory notes
Citations
General and cited sources
Further reading
External links
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