World population

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Map of countries by population—China and India, the only two countries to have a population greater than one billion, together possess more than a third of the world's population. (See List of countries by population.)
Map of countries by population—China and India, the only two countries to have a population greater than one billion, together possess more than a third of the world's population. (See List of countries by population.)
Population by continent as a percentage of world population (1750–2005)
Population by continent as a percentage of world population (1750–2005)

The world population is the total number of living humans on Earth at a given time. As of May 2008, the world's population is believed to be just over 6.7 billion.[1][2] In line with population projections, this figure continues to grow at rates that were unprecedented before the 20th century, although the rate of increase has almost halved since its peak, which was reached in 1963, of 2.2 percent per year. The world's population, on its current growth trajectory, is expected to reach nearly 9 billion by the year 2042.[3][4]

Contents

[edit] Population figures

Censuses taken between 300–400 CE[dubious – discuss] showed over 50 million people living in the combined eastern and western Roman empire.[citation needed](citation Dr. Kenneth W. Harl, tulane.edu)

Below is a table with historical and predicted population figures shown in millions.[5][6][7] The availability of historical population figures varies by region. (Note: These projections here are not kept up to date.) Please see World population estimates for more figures.

World historical and predicted populations (in millions)[8]
Region 1750 1800 1850 1900 1950 1999 2050 2150
World 791 978 1,262 1,650 2,521 5,978 8,909 9,746
Africa 106 107 111 133 221 767 1,766 2,308
Asia 502 635 809 947 1,402 3,634 5,268 5,561
Europe 163 203 276 408 547 729 628 517
Latin America and the Caribbean * 16 24 38 74 167 511 809 912
Northern America * 2 7 26 82 172 307 392 398
Oceania 2 2 2 6 13 30 46 51
World historical and predicted populations by percentage distribution
Region 1750 1800 1850 1900 1950 1999 2050 2150
World 100 100 100 100 100 100 100 100
Africa 13.4 10.9 8.8 8.1 8.8 12.8 19.8 23.7
Asia 63.5 64.9 64.1 57.4 55.6 60.8 59.1 57.1
Europe 20.6 20.8 21.9 24.7 21.7 12.2 7.0 5.3
Latin America and the Caribbean * 2.0 2.5 3.0 4.5 6.6 8.5 9.1 9.4
Northern America * 0.3 0.7 2.1 5.0 6.8 5.1 4.4 4.1
Oceania 0.3 0.2 0.2 0.4 0.5 0.5 0.5 0.5
Estimated world population at various dates (in thousands)
Year World Africa Asia Europe Latin America * Northern America* Oceania Notes
70,000 BCE 2 [9]
10,000 BCE 1,000
9000 BCE 3,000
8000 BCE 5,000 [10]
7000 BCE 7,000
6000 BCE 10,000
5000 BCE 15,000
4000 BCE 20,000
3000 BCE 25,000
2000 BCE 35,000
1000 BCE 50,000 [10]
500 BCE 100,000 [10]
1 200,000 [11]
1000 310,000
1750 791,000 106,000 502,000 163,000 16,000 2,000 2,000
1800 978,000 107,000 635,000 203,000 24,000 7,000 2,000
1850 1,262,000 111,000 809,000 276,000 38,000 26,000 2,000
1900 1,650,000 133,000 947,000 408,000 74,000 82,000 6,000
1950 2,518,629 221,214 1,398,488 547,403 167,097 171,616 12,812
1955 2,755,823 246,746 1,541,947 575,184 190,797 186,884 14,265
1960 2,981,659 277,398 1,674,336 601,401 209,303 204,152 15,888
1965 3,334,874 313,744 1,899,424 634,026 250,452 219,570 17,657
1970 3,692,492 357,283 2,143,118 655,855 284,856 231,937 19,443
1975 4,068,109 408,160 2,397,512 675,542 321,906 243,425 21,564
1980 4,434,682 469,618 2,632,335 692,431 361,401 256,068 22,828
1985 4,830,979 541,814 2,887,552 706,009 401,469 269,456 24,678
1990 5,263,593 622,443 3,167,807 721,582 441,525 283,549 26,687
1995 5,674,380 707,462 3,430,052 727,405 481,099 299,438 28,924
2000 6,070,581 795,671 3,679,737 727,986 520,229 315,915 31,043
2005 6,453,628 887,964 3,917,508 724,722 558,281 332,156 32,998**

* Northern America indicates the northern countries and territories of North America: Canada, the United States, Greenland, Bermuda, and St. Pierre and Miquelon. This should not be confused with the term "North America" which typically includes Mexico. The United Nations data includes Mexico as part of Latin America.

** This figure is disputed.

[edit] Rate of increase

Main article: Population growth
Population evolution in different continents. The vertical axis is logarithmic and is millions of people.
Population evolution in different continents. The vertical axis is logarithmic and is millions of people.

Different regions have different rates of population growth, but in the unusual case of the 20th century, the world saw the biggest increase in its population in human history due to medical advances and massive increase in agricultural productivity made by the Green Revolution.

In 2000, the United Nations estimated that the world's population was then growing at the rate of 1.14% (or about 75 million people) per year,[12] down from a peak of 86 million per year in 1987. In the last few centuries, the number of people living on Earth has increased many times over. By the year 2000, there were 10 times as many people on Earth as there were 300 years ago. According to data from the CIA's 2005–2006 World Factbooks, the world human population increased by 203,800 every day.[13] The 2007 CIA factbook increased this to 211,090 people every day.

Globally, the population growth rate has been steadily declining from its peak of 2.19% in 1963, but growth remains high in the Middle East and Sub-Saharan Africa.[14]

In some countries there is negative population growth (i.e. net decrease in population over time), especially in Central and Eastern Europe (mainly due to low fertility rates) and Southern Africa (due to the high number of HIV-related deaths). Within the next decade, Japan and some countries in Western Europe are also expected to encounter negative population growth due to sub-replacement fertility rates.

Population growth which exceeds the carrying capacity of an area or environment results in overpopulation. Conversely, such areas may be considered "underpopulated" if the population is not large enough to maintain an economic system; however, many who do not view overpopulation as a serious problem fail to consider the sustainability of economic systems, the environmental degradation caused, and the ecological footprint of the existing population.

The United Nations states that population growth is rapidly declining due to the demographic transition. The world population is expected to peak at 9.2 billion in 2075. [1]

Population (est.) 10,000 BCE – 2000 CE.

Population (est.) in log y scale

World population 1950–2000

Increase rate 1950–2000

[edit] Milestones

World population estimates milestones .
Population (in billions) 1 2 3 4 5 6 7 8 9
Year 1804 1927 1961 1974 1987 1999 2011 2024 2042
Years elapsed 123 34 13 13 12 12 13 18

These numbers show that the world's population has tripled in 72 years, and doubled in 38 years up to the year 1999. Including some more estimates, the world population has been doubled or will double in the following years (with two different starting points). Note how, during the 2nd millennium, each doubling has taken roughly half as long as the previous doubling.

Starting at 250 millions Starting at 375 millions
Population
(in billions)		 0.25 0.5 1 2 4 8 0.375 0.75 1.5 3 6
Year 950 1600 1804 1927 1974 2024 1420 1720 1875 1961 1999
Years elapsed 650 204 123 47 50 300 155 86 38

[edit] Population distribution

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Population density map of the world in 1994, when the world's population was at 5.6 billion; Observe the high densities in the Indo-Gangetic and North China Plains, the Sichuan Basin, the Nile river delta, Southern Japan, Western Europe, the Indonesian island of Java, Central America (especially El Salvador, the Americas' most densely populated nation), and the United States' BosWash megalopolis.
Population density map of the world in 1994, when the world's population was at 5.6 billion; Observe the high densities in the Indo-Gangetic and North China Plains, the Sichuan Basin, the Nile river delta, Southern Japan, Western Europe, the Indonesian island of Java, Central America (especially El Salvador, the Americas' most densely populated nation), and the United States' BosWash megalopolis.

Asia accounts for over 60% of the world population with almost 3.8 billion people. People's Republic of China and India alone comprise 20% and 16% respectively. Africa follows with 840 million people, 12% of the world population. Europe's 710 million people make up 11% of the world's population. North America is home to 514 million (8%), South America to 371 million (5.3%), and Australia 21 million.

[edit] The 15 most populous nations

The 15 most populous nations
The 15 most populous nations

Approximately 4.3 billion people live in these 15 countries, representing roughly two-thirds of the world's population. If added together, all nations in the European Union, with 494 million people – about 7.3% of world's population in 2006 – would be third in the list below.

Country[15] Population
(millions)		 Percentage
China 1,320 19.84%
India 1,130 16.96%
United States 304 4.56%
Indonesia 232 3.47%
Brazil 187 2.80%
Pakistan 163 2.44%
Bangladesh 159 2.38%
Nigeria 148 2.22%
Russia 142 2.13%
Japan 128 1.92%
Mexico 107 1.60%
Philippines 89 1.33%
Vietnam 84 1.31%
Germany 82 1.23%
Egypt 81 1.13%
Population by region, 2007
Population by region, 2007

[edit] Ethnicity

Main article: List of ethnic groups

The world is made up of hundreds of thousands of ethnic groups, and due to mass migration across the planet over millennia, it is impossible to tell how many people belonging to a certain ethnic group inhabit the earth. The single largest ethnic group on the planet by far is Han Chinese, which represents 19.73% of the global population, for comparison 6.06% of the planet's population is of full or partial Spanish ancestry, and on a wider scale 14.2% of earth's population is of Sub-Saharan descent (those identifying as 'Black').

[edit] Demographics of youth

According to the 2006 CIA World Factbook, around 27% of the world's population is below 15 years of age.[16]

Before adding mortality rates, the 1990s saw the greatest number of raw births worldwide, especially in the years after 1995, despite the fact that the birth rate was not as high as in the 1960s. In fact, because of the 160 million-per-year raw births after 1995, the time it took to reach the next billion reached its fastest pace (only 12 years), as world population reached 6 billion people in 1999, when at the beginning of the decade, the reaching was designated for the year 2000, by most demographers. People aged 7 through 17 make up these births, today.

1985–1990 marked the period with the fastest yearly population change in world history. Even though the early 1960s had a greater growth rate than in the mid and late 1980s, the population change hovered around 83 million people in the five-year period, with an all-time growth change of nearly 88 million in 1990. The reason is because the world's population was greater in the mid and late 1980s (around 5 billion) than in the early 1960s (around 3 billion), which meant that the growth rate in the 1980s was no factor on the dramatic population change. People aged 17 to 22 make up these births, today.

[edit] Forecast of world population

Main article: World population estimates
See also: Overpopulation
U.S. Census Bureau estimates[17]
Year Population
(in billions)
2010 6.8
2020 7.6
2030 8.3
2040 8.9
2050 9.4

In the long run, the future population growth of the world is difficult to predict. Birth rates are declining slightly on average, but vary greatly between developed countries (where birth rates are often at or below replacement levels), developing countries, and different ethnicities. Death rates can change unexpectedly due to disease, wars and catastrophes, or advances in medicine. The UN itself has issued multiple projections of future world population, based on different assumptions. Over the last 10 years, the UN had consistently revised these projections downward, until the 2006 revision issued March 14, 2007 revised the 2050 mid range estimate upwards by 273 million.

Alternately, the United States Census Bureau issued a revised forecast for world population that increased its projection for the year 2050 to above 9.4 billion people (which was the UN's 1996 projection for 2050), up from 9.1 billion people.

Other projections of population growth predict that the world's population will eventually crest, though it is uncertain exactly when or how. In some scenarios, the population will crest as early as the mid-21st century at under 9 billion, due to gradually decreasing birth rates, (the "low variant" of [5]), The "high variant" from the same source gives a population between 10 and 11 billion in 2050.

In other scenarios, disasters triggered by the growing population's demand for scarce resources will eventually lead to a sudden population crash, or even a Malthusian catastrophe (also see overpopulation and food security).

UN estimates (in thousands).[5][18][19]
Year World Africa Asia Europe Latin America US and Canada Oceania
2010 6,830,283 984,225 (14.4%) 4,148,948 (60.7%) 719,714 (10.5%) 594,436 (8.7%) 348,139 (5.1%) 34,821 (0.5%)
2015 7,197,247 1,084,540 (15.1%) 4,370,522 (60.7%) 713,402 (9.9%) 628,260 (8.7%) 363,953 (5.1%) 36,569 (0.5%)
2020 7,540,237 1,187,584 (15.7%) 4,570,131 (60.6%) 705,410 (9.4%) 659,248 (8.7%) 379,589 (5.0%) 38,275 (0.5%)
2025 7,851,455 1,292,085 (16.5%) 4,742,232 (60.4%) 696,036 (8.9%) 686,857 (8.7%) 394,312 (5.0%) 39,933 (0.5%)
2030 8,130,149 1,398,004 (17.2%) 4,886,647 (60.1%) 685,440 (8.4%) 711,058 (8.7%) 407,532 (5.0%) 41,468 (0.5%)
2035 8,378,184 1,504,179 (18.0%) 5,006,700 (59.8%) 673,638 (8.0%) 731,591 (8.7%) 419,273 (5.0%) 42,803 (0.5%)
2040 8,593,591 1,608,329 (18.7%) 5,103,021 (59.4%) 660,645 (8.0%) 747,953 (8.7%) 429,706 (5.0%) 43,938 (0.5%)
2045 8,774,394 1,708,407 (19.5%) 5,175,311 (59.0%) 646,630 (7.4%) 759,955 (8.7%) 439,163 (5.0%) 44,929 (0.5%)
2050 8,918,724 1,803,298 (20.2%) 5,217,202 (58.5%) 653,323 (7.3%) 767,685 (8.6%) 447,931 (5.0%) 45,815 (0.5%)

[edit] Predictions based on our growing population

In 1798, Thomas Malthus incorrectly predicted that population growth would eventually outrun food supply in the middle of the 19th century, resulting in catastrophe. In 1968, Paul R. Ehrlich reignited this argument with his book The Population Bomb, which helped give the issue significant attention throughout the 1960s and 1970s. The dire predictions of Ehrlich and other neo-Malthusians were vigorously challenged by a number of economists, notably Julian Simon.

On the opposite end of the spectrum there are a number of people who argue that today's low fertility rates in Europe, North America, Japan and Australia, combined with mass immigration, will have severe negative consequences for these countries.[20]

Child poverty has been linked to people having children before they have the means to care for them.[21] More recently, some scholars have put forward the Doomsday argument applying Bayesian probability to world population to argue that the end of humanity will come sooner than we usually think.[22]

It should be noted that between 1950 and 1984, as the Green Revolution transformed agriculture around the globe, world grain production increased by 250%. The energy for the Green Revolution was provided by fossil fuels in the form of fertilizers (natural gas), pesticides (oil), and hydrocarbon fueled irrigation.[23] The peaking of world hydrocarbon production (Peak oil) may test Malthus and Ehrlich critics.[24][25] As of May 2008, increased farming for use in biofuels,[26] world oil prices at over $120 a barrel,[27] global population growth,[28] climate change,[29] loss of agricultural land to residential and industrial development,[30][31] and growing consumer demand in China and India[32] have pushed up the price of grain.[33] Food riots have recently taken place in many countries across the world.[34][35][36]

The world population has grown by about four billion since the beginning of the Green Revolution and most believe that, without the Revolution, there would be greater famine and malnutrition than the UN presently documents (approximately 850 million people suffering from chronic malnutrition in 2005).[37]

[edit] Number of humans who have ever lived

Estimates of the total number of people who have ever lived range approximately from 45 billion to 125 billion[citation needed]. Many of the more robust estimates fall into the range of 90 to 110 billion humans[citation needed]. It is impossible to make a precise count of the number of human beings who have ever lived for the following reasons:

  • The set of specific characteristics which define a human being and distinguish early Homo sapiens from earlier or related species continues to be a subject of intense research and debate. It is thus not possible to know when to begin the count, nor which hominids to include.
  • Even if the scientific community reached wide consensus regarding which characteristics distinguished human beings, it would be nearly impossible to pinpoint the time of their first appearance to even the nearest millennium because the fossil record is simply too sparse. Only a few thousand fossils of early humans have been found, most no bigger than a tooth or a knucklebone. These bone fragments are used to extrapolate the population distribution of millions of early human beings spread across the continents.
  • Robust statistical data only exists for the last two or three centuries. Until the late 18th century, few nations, kingdoms, or empires had ever performed an accurate census. In many early attempts, the focus was on counting merely a subset of the people for purposes of taxation or military service[citation needed]. Even with the advent of agencies such as the United States Bureau of the Census, reliable census methods and technologies continue to evolve. All estimates of population sizes preceding the 18th century are estimates, and thus the margin of error for the total number of humans who have ever lived should be in the billions, or even tens of billions of people.

"Guesstimating the number of people ever born... requires selecting population sizes for different points from antiquity to the present and applying assumed birth rates to each period..."[38]

According to one set of calculations based on 2002 data:[38]

  • The number who have ever been born is around 106 000 000 000.
  • The world population in mid-2002 was approximately 6 215 000 000
  • The percentage of those ever born who were living in 2002 was approximately 5.8%

[edit] References

  1. ^ CIA's The World Factbook (see also The World Factbook)
  2. ^ World POPClock Projection, U.S. Census Bureau
  3. ^ World Population Clock - Worldometers
  4. ^ International Data Base (IDB) - World Population
  5. ^ a b c World population prospects: the 2004 revision population database
  6. ^ The World at un.org
  7. ^ Population Growth over Human History
  8. ^ UN report 2004 data
  9. ^ http://www.breitbart.com/article.php?id=080425101050.cni2ks3u&show_article=1
  10. ^ a b c an average of 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.
  11. ^ The range of figures from different sources as listed at the US Census Bureau's Historical Estimates of World Population put the population at 1 CE between 170 million to 400 million.
  12. ^ census.gov
  13. ^ Current world population (ranked)
  14. ^ Ron Nielsen, The little green handbook, Picador, New York (2006) ISBN 0-312-42581-3
  15. ^ From DSW-Datareport 2006 ("Deutsche Stiftung Weltbevölkerung")
  16. ^ Age structure of the world – 2006 CIA World Factbook
  17. ^ U.S. Census Bureau - International Data Base (IDB)
  18. ^ The World at Six Billion
  19. ^ Population Growth over Human History
  20. ^ The Death of the West: How Dying Populations and Immigrant Invasions Imperil Our Country and Civilization (ISBN 0-312-30259-3), by Patrick Buchanan, The Empty Cradle: How Falling Birthrates Threaten World Prosperity (ISBN 0-465-05050-6), by Longman, and Fewer: How the New Demography of Depopulation Will Shape Our Future (ISBN 1-56663-606-X), by Wattenberg
  21. ^ Population bomb still ticking away - 20 Mar 2007 - NZ Herald
  22. ^ DIE OFF - a population crash resource page
  23. ^ Eating Fossil Fuels |EnergyBulletin.net
  24. ^ Peak Oil: the threat to our food security
  25. ^ Peak Oil And Famine:Four Billion Deaths
  26. ^ 2008: The year of global food crisis
  27. ^ The global grain bubble
  28. ^ Food crisis will take hold before climate change, warns chief scientist
  29. ^ Global food crisis looms as climate change and fuel shortages bite
  30. ^ Experts: Global Food Shortages Could ‘Continue for Decades'
  31. ^ Has Urbanization Caused a Loss to Agricultural Land?
  32. ^ The World's Growing Food-Price Crisis
  33. ^ The cost of food: Facts and figures
  34. ^ Riots and hunger feared as demand for grain sends food costs soaring
  35. ^ Already we have riots, hoarding, panic: the sign of things to come?
  36. ^ Feed the world? We are fighting a losing battle, UN admits
  37. ^ The limits of a Green Revolution?
  38. ^ a b How Many People Have Ever Lived on Earth? by Carl Haub, 2002; calculated from a start date of 50 000 years BCE.

[edit] Further resources

  • There is a map that is rescaled in order to display every country according to its population size. It is available at the University of Sheffield 'Worldmapper'[2] site.[1]
  • Population patterns and trends can be explored on the GeoHive interactive world atlas.[2]

[edit] See also

[edit] External links