![Illustration_of_contemporary_and_past_human_populations_Our_World_in_Data](https://upload.wikimedia.org/wikipedia/commons/d/d2/Illustration_of_contemporary_and_past_human_populations_Our_World_in_Data.png)
This article lists current estimates of the
world population
In demographics, the world population is the total number of humans currently living. It was estimated by the United Nations to have exceeded 8 billion in November 2022. It took over 200,000 years of human prehistory and history for the ...
in history. In summary, estimates for the progression of world population since the
Late Middle Ages
The Late Middle Ages or Late Medieval Period was the Periodization, period of European history lasting from AD 1300 to 1500. The Late Middle Ages followed the High Middle Ages and preceded the onset of the early modern period (and in much of Eur ...
are in the following ranges:
Estimates for pre-modern times are necessarily fraught with great uncertainties, and few of the published estimates have
confidence interval
In frequentist statistics, a confidence interval (CI) is a range of estimates for an unknown parameter. A confidence interval is computed at a designated ''confidence level''; the 95% confidence level is most common, but other levels, such as 9 ...
s; in the absence of a straightforward means to assess the error of such estimates, a rough idea of expert consensus can be gained by comparing the values given in independent publications. Population estimates cannot be considered accurate to more than two decimal digits; for example, the world population for the year 2012 was estimated at 7.02, 7.06, and 7.08 billion by the
United States Census Bureau
The United States Census Bureau (USCB), officially the Bureau of the Census, is a principal agency of the U.S. Federal Statistical System, responsible for producing data about the American people and economy. The Census Bureau is part of the ...
, the
Population Reference Bureau
The Population Reference Bureau (PRB) is a private, nonprofit organization specializing in collecting and supplying statistics necessary for research and/or academic purposes focused on the environment, and health and structure of populations. The ...
, and the
United Nations Department of Economic and Social Affairs
The United Nations Department of Economic and Social Affairs (UN DESA) is part of the United Nations Secretariat and is responsible for the follow-up to major United Nations Summits and Conferences, as well as services to the United Nations Econ ...
, respectively, corresponding to a spread of estimates of the order of 0.8%.
Deep prehistory
![Population curve](https://upload.wikimedia.org/wikipedia/commons/b/b7/Population_curve.svg)
As a general rule, the confidence of estimates on historical world population decreases for the more distant past. Robust population data exist only 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 Achaemenid Empire or Achaemenian Empire (; peo, wikt:π§πππΆ, π§ππ, , ), also called the First Persian Empire, was an History of Iran#Classical antiquity, ancient Iranian empire founded by Cyrus the Great in 550 BC. Bas ...
, the focus was on counting merely a subset of the population for purposes of taxation or military service. Published estimates for the 1st century ("
AD 1") suggest uncertainty of the order of 50% (estimates range between 150 and 330
million). Some estimates extend their timeline into deep prehistory, to "
10,000 BC", i.e., the
early Holocene
In the geologic time scale, the Greenlandian is the earliest age or lowest stage of the Holocene Epoch or Series, part of the Quaternary. Beginning in 11,650 BP (9701 BCE or 300 HE) and ending 8,276 BP (6237 BCE or 3764 HE), it is the earlie ...
, when world population estimates range roughly between 1 and 10
million (with an uncertainty of up to an order of magnitude).
Estimates for yet deeper prehistory, into the
Paleolithic
The Paleolithic or Palaeolithic (), also called the Old Stone Age (from Greek: ΟαλαιΟΟ ''palaios'', "old" and Ξ»Ξ―ΞΈΞΏΟ ''lithos'', "stone"), is a period in human prehistory that is distinguished by the original development of stone too ...
, are of a different nature. At this time, human populations consisted entirely of non-sedentary
hunter-gatherer
A traditional hunter-gatherer or forager is a human living an ancestrally derived lifestyle in which most or all food is obtained by foraging, that is, by gathering food from local sources, especially edible wild plants but also insects, fungi, ...
populations, with
anatomically modern humans
Early modern human (EMH) or anatomically modern human (AMH) are terms used to distinguish ''Homo sapiens'' (the only extant Hominina species) that are anatomically consistent with the range of phenotypes seen in contemporary humans from extin ...
existing alongside
archaic human varieties, some of which are still ancestral to the modern human population due to
interbreeding with modern humans during the
Upper Paleolithic
The Upper Paleolithic (or Upper Palaeolithic) is the third and last subdivision of the Paleolithic or Old Stone Age. Very broadly, it dates to between 50,000 and 12,000 years ago (the beginning of the Holocene), according to some theories coin ...
. Estimates of the size of these populations are a topic of
paleoanthropology
Paleoanthropology or paleo-anthropology is a branch of paleontology and anthropology which seeks to understand the early development of anatomically modern humans, a process known as hominization, through the reconstruction of evolutionary kinship ...
. A late human
population bottleneck
A population bottleneck or genetic bottleneck is a sharp reduction in the size of a population due to environmental events such as famines, earthquakes, floods, fires, disease, and droughts; or human activities such as specicide, widespread violen ...
is postulated by some scholars at approximately 70,000 years ago, during the
Toba catastrophe, when ''
Homo sapiens
Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, ...
'' population may have dropped to as low as between 1,000 and 10,000
individuals.
[
] For the time of speciation of ''
Homo sapiens
Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, ...
'', some 200,000 years ago, an
effective population size
The effective population size (''N'e'') is a number that, in some simplified scenarios, corresponds to the number of breeding individuals in the population. More generally, ''N'e'' is the number of individuals that an idealised population wo ...
of the order of 10,000 to 30,000
individuals has been estimated, with an actual "census population" of early ''Homo sapiens'' of roughly 100,000 to 300,000 individuals.
Estimates regarding the questions of "how many people have ever lived?" or "what percentage of people who have ever lived are alive today?" can be traced to the 1970s. The more dramatic phrasing of "the living outnumber the dead" also dates to the 1970s, a time of
population explosion
Overpopulation or overabundance is a phenomenon in which a species' population becomes larger than the carrying capacity of its environment. This may be caused by increased birth rates, lowered mortality rates, reduced predation or large scale m ...
and growing fears of
human overpopulation
Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, ...
in the wake of
decolonization
Decolonization or decolonisation is the undoing of colonialism, the latter being the process whereby imperial nations establish and dominate foreign territories, often overseas. Some scholars of decolonization focus especially on separatism, in ...
and before the adoption of China's
one-child policy
The term one-child policy () refers to a population planning initiative in China implemented between 1980 and 2015 to curb the country's population growth by restricting many families to a single child. That initiative was part of a much br ...
. The claim that "the living outnumber the dead" was never accurate.
Arthur C. Clarke in ''
2001: A Space Odyssey'' (1968) has the claim that "Behind every man, now alive stand 30
ghosts, for that is the ratio by which the dead outnumber the living", which was roughly accurate at the time of writing.
Recent estimates of the "total number of people who have ever lived" are in the order of 100 billion.
The answer depends on the definition of "people", i.e., is only ''
Homo sapiens
Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, ...
'' to be counted, or all of the genus ''
Homo
''Homo'' () is the genus that emerged in the (otherwise extinct) genus ''Australopithecus'' that encompasses the extant species ''Homo sapiens'' ( modern humans), plus several extinct species classified as either ancestral to or closely relate ...
'', but due to the small population sizes in the
Lower Paleolithic
The Lower Paleolithic (or Lower Palaeolithic) is the earliest subdivision of the Paleolithic or Old Stone Age. It spans the time from around 3 million years ago when the first evidence for stone tool production and use by hominins appears in ...
, the order of magnitude of the estimate is not affected by the choice of cut-off date substantially more than by the uncertainty of estimates throughout the Neolithic to Iron Age. Importantly, the estimate is also affected by the estimate of
infant mortalities vs.
stillborn
Stillbirth is typically defined as fetal death at or after 20 or 28 weeks of pregnancy, depending on the source. It results in a baby born without signs of life. A stillbirth can result in the feeling of guilt or grief in the mother. The ter ...
infants, due to the very high rate of infant mortality throughout the pre-modern period. An estimate on the "total number of people who have ever lived" as of 1995 was calculated by Haub (1995) at "about 105 billion births since the dawn of the human race" with a cut-off date at 50,000 BC (beginning of the Upper Paleolithic), and inclusion of a high infant mortality rate throughout pre-modern history.
Historical population
Before 1950
The following table uses
astronomical year numbering
Astronomical year numbering is based on AD/ CE year numbering, but follows normal decimal integer numbering more strictly. Thus, it has a year 0; the years before that are designated with negative numbers and the years after that are designated w ...
for dates, negative numbers corresponding roughly to the corresponding year BC (for example, β10000
=
10,001
BC, etc.). The table starts counting approximately 10,000 years before present, or around 8,000 BC, during the middle
Greenlandian
In the geologic time scale, the Greenlandian is the earliest age or lowest stage of the Holocene Epoch or Series, part of the Quaternary. Beginning in 11,650 BP (9701 BCE or 300 HE) and ending 8,276 BP (6237 BCE or 3764 HE), it is the earlies ...
, about 1,700 years after the end of the
Younger Dryas
The Younger Dryas (c. 12,900 to 11,700 years BP) was a return to glacial conditions which temporarily reversed the gradual climatic warming after the Last Glacial Maximum (LGM, c. 27,000 to 20,000 years BP). The Younger Dryas was the last stage ...
and 1,800 years before the
8.2-kiloyear event
In climatology, the so-called "8.2-kiloyear event" was a sudden decrease in global temperatures that occurred approximately 8,200 years before the present ( BP), that is, 6,251 BC. It defines the start of the Northgrippian age in the Holocene ...
.
From the beginning of the
early modern period until the 20th century, world population has been characterized by a faster-than-exponential growth. For the period of
Classical antiquity
Classical antiquity (also the classical era, classical period or classical age) is the period of cultural history between the 8th century BC and the 5th century AD centred on the Mediterranean Sea, comprising the interlocking civilizations of ...
to the
Middle Ages
In the history of Europe, the Middle Ages or medieval period lasted approximately from the late 5th to the late 15th centuries, similar to the post-classical period of global history. It began with the fall of the Western Roman Empire a ...
, roughly 500
BC to AD 1500, there was also a general tendency of growth (estimated at a factor 4 to 5 over the 2,000-year period), but not strictly
monotonic
In mathematics, a monotonic function (or monotone function) is a function between ordered sets that preserves or reverses the given order. This concept first arose in calculus, and was later generalized to the more abstract setting of order ...
: A noticeable dip in world population is assumed due to the
Black Death
The Black Death (also known as the Pestilence, the Great Mortality or the Plague) was a bubonic plague pandemic occurring in Western Eurasia and North Africa from 1346 to 1353. It is the most fatal pandemic recorded in human history, causi ...
in the mid-14th century.
[
]
1950 to present
For times after World War
A world war is an international conflict which involves all or most of the world's major powers. Conventionally, the term is reserved for two major international conflicts that occurred during the first half of the 20th century, World WarI (1914 ...
II, demographic data of some accuracy becomes available for a significant number of countries, and population estimates are often given as grand totals of numbers (typically given by country) of widely diverging accuracies. Some sources give these numbers rounded to the nearest million or the nearest thousand, while others give them without any rounding.
Taking these numbers at face value would be false precision
False precision (also called overprecision, fake precision, misplaced precision and spurious precision) occurs when numerical data are presented in a manner that implies better precision than is justified; since precision is a limit to accuracy ( ...
; in spite of being stated to four, seven, or even ten digits, they should not be interpreted as accurate to more than three digits at best (estimates by the United States Census Bureau
The United States Census Bureau (USCB), officially the Bureau of the Census, is a principal agency of the U.S. Federal Statistical System, responsible for producing data about the American people and economy. The Census Bureau is part of the ...
and by the United Nations
The United Nations (UN) is an intergovernmental organization whose stated purposes are to maintain international peace and international security, security, develop friendly relations among nations, achieve international cooperation, and be ...
differ by about 0.5β1.5%).
By world region
Population estimates for world regions based on Maddison (2007),[Angus Maddison, The World Economy: Historical Statistics, Statistical Appendix (2007, ggdc.net).
Estimates cited are for the beginning of the 1st millennium ("year 0"), the beginning of the 2nd millennium ("year 1000"), and for the beginning each century since the 16th (years 1820 and 1913 are given for the 19th and 20th century, respectively, as Maddison presents detailed estimates for these years), and a projection for the year 2030.] in millions. The row showing total world population includes the average growth rate per year over the period separating each column from the preceding one.
World Population Estimates, 20 Countries and Regional Totals, 0β2000 AD (in thousands)
References
Further reading
*
*
External links
Historical Estimates of World Population
β United States Census Bureau
The United States Census Bureau (USCB), officially the Bureau of the Census, is a principal agency of the U.S. Federal Statistical System, responsible for producing data about the American people and economy. The Census Bureau is part of the ...
{{Population
Estimates
{{otheruses, Estimate (disambiguation)
In the Westminster system of government, the ''Estimates'' are an outline of government spending for the following fiscal year presented by the cabinet to parliament. The Estimates are drawn up by bureaucrat ...
Demographic history