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World population estimates from 1800 to 2100, based on "high", "medium" and "low" United Nations projections in 2010 (colored red, orange and green) and US Census Bureau historical estimates (in black). Actual recorded population figures (as of 2010) are colored in blue. According to the highest estimate, the world population may rise to 16 billion by 2100; according to the lowest estimate, it may decline to 6 billion.

In demographics, the world population is the total number of humans living on Earth. As of July 2015, it was estimated at 1 Trillion.[1] The United Nations estimates it will increase to 11.2 billion in the year 2100.[1]

The world population has experienced continuous growth since the end of the Great Famine and the Black Death in 1350, when it was near 370 million.[2] The highest growth rates – global population increases above 1.8% per year – occurred briefly during the 1950s, and for longer during the 1960s and 1970s. The global growth rate peaked at 2.2% in 1963, and has declined to 1.1% as of 2012.[3] Total annual births were highest in the late 1980s at about 139 million,[4] and are now expected to remain essentially constant at their 2011 level of 135 million,[5] while deaths number 56 million per year, and are expected to increase to 80 million per year by 2040.[6] World population reached 7 billion in October 2011 according to the United Nations Population Fund,[7][8][9] and in March 2012 according to the United States Census Bureau.[10]

The 2012 UN 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.[11][12] 2003 UN Population Division population projections for the year 2150 range between 3.2 and 24.8 billion.[13] One of many independent mathematical models supports the lower estimate,[14] while a 2014 estimate forecasts between 9.3 and 12.6 billion in 2100, and continued growth thereafter.[15][16] Some analysts have questioned the sustainability of further world population growth, highlighting the growing pressures on the environment, global food supplies, and energy resources.[17][18][19]

Some scholars have estimated the total number of humans who have ever lived, arriving at numbers ranging from 100 to 115 billion.[20][21]

World population (millions)[22]
# Top ten most populous countries 1990 2008 2025*
1 China 1,141 1,333 1,458
2 India 849 1,140 1,398
3 United States 250 304 352
4 Indonesia 178 228 273
5 Brazil 150 192 223
6 Pakistan 108 166 226
7 Bangladesh 116 160 198
8 Nigeria 94 151 208
9 Russia 149 143 137
10 Japan 124 128 126
World total 5,267 6,689 8,004
Top ten most populous (%) 60.0% 58.9% 57.5%
1 Asia 1,613 2,183 2,693
+ China 1,141 1,333 1,458
+ OECD Pacific* 187 202 210
2 Africa 634 984 1,365
3 Europe* 564 603 659
+ Russia 149 143 137
+ 11 Post-Soviet Republics* 134 136 146
4 Latin America 355 462 550
5 North America* 359 444 514
6 Middle East 132 199 272
Australia 17 22 28
European Union 473 499 539
US & Canada 278 338 392
Post-Soviet Union 291 286 289
Geographical definitions as in IEA Key Stats 2010 p. 66
Notes:
  • Europe = OECD Europe + Non-OECD Europe and
    excluding Russia and including Estonia, Latvia and Lithuania
  • 11 Soviet Republics = USSR excluding Russia and Baltic states
  • North America = US, Canada, Mexico
  • OECD Pacific = Australia, Japan, Korea, New Zealand
  • 2025 = with constant annual 2007/2008 growth until 2025

Population by region

Six of Earth's seven continents are permanently inhabited on a large scale. Asia is the most populous continent, with its 4.3 billion inhabitants accounting for 60% of the world population. The world's two most populated countries alone, China and India, together constitute about 37% of the world's population. Africa is the second most populated continent, with around 1 billion people, or 15% of the world's population. Europe's 733 million people make up 12% of the world's population as of 2012, while the Latin American and Caribbean regions are home to around 600 million (9%). Northern America, primarily consisting of the United States and Canada, has a population of around 352 million (5%), and Oceania, the least-populated region, has about 35 million inhabitants (0.5%).[23] 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.[24]

Population by continent

Continent Density
(inhabitants/km2)
Population
(millions, 2013 estimates)
Most populous country Most populous city (metropolitan area)
Asia 96.4 4,298  China (1,361,000,000)[25] Japan Greater Tokyo Area (35,676,000)
Africa 36.7 1,111  Nigeria (178,517,000) Nigeria Lagos (21,000,000)
Europe 72.9 742  Russia (143,700,000;
approx. 110 million in Europe)
Russia Moscow (19,468,664)
North America[26] 22.9 565  United States (317,996,000) Mexico Mexico City/Metro Area (8,851,080 / 21,163,226)
South America 22.8 407  Brazil (201,032,714) Brazil São Paulo City/Metro Area (11,316,149 / 27,640,577)
Oceania 4.5 38  Australia (23,475,992) Australia Sydney (4,840,600)
Antarctica 0.0003
(varies)
0.004 in summer
(non-permanent, varies)[24]
N/A[note 1] McMurdo Station (1,200) (non-permanent, varies)

History

Antiquity and Middle Ages

The world population in 35,000 BCE is estimated to have been around 3 million people, all of whom subsisted as hunter-gatherers.[27] The population had increased to around 15 million at the time agriculture emerged in around 10,000 BCE.[28] By contrast, it is estimated that around 50–60 million people lived in the combined eastern and western Roman Empire in the 4th century CE.[29]

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 CE.[30] The population of Europe was more than 70 million in 1340.[31] 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;[32] it took 200 years for population figures to recover.[33] The population of China decreased from 123 million in 1200 to 65 million in 1393,[34] presumably due to a combination of Mongol invasions, famine, and plague.[35]

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.[36] England's population reached an estimated 5.6 million in 1650, up from an estimated 2.6 million in 1500.[37] New crops that were brought to Asia and Europe from the Americas by Spanish colonists in the 16th century are believed to have contributed to population growth.[38][39] Since their introduction to Africa by Portuguese traders in the 16th century,[40] maize and cassava have similarly replaced traditional African crops as the most important staple food crops grown on the continent.[41]

Around 300 BCE, the population of India was between 100 million and 140 million.[42] The population of India in 1600 was around 100 million. Hence, from 300 BCE to 1600, India's population was more or less stable.[43]

The pre-Columbian North American population probably numbered somewhere between 2 million and 18 million.[44] Encounters between European explorers and populations in the rest of the world often introduced local epidemics of extraordinary virulence.[45] According to the most extreme scholarly claims, as many as 90% of the Native American population of the New World died due to Old World diseases such as smallpox, measles and influenza.[46] Over the centuries, the Europeans had developed high degrees of immunity to these diseases, while the indigenous peoples had no such immunity.[47]

Modern era

Map showing urban areas with at least one million inhabitants in 2006. Only 3% of the world's population lived in cities in 1800; this proportion had risen to 47% by 2000, and reached 50.5% by 2010.[48] By 2050, the proportion may reach 70%.[49]

During the European Agricultural and Industrial Revolutions, the life expectancy of children increased dramatically.[50] 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.[51][52] Between 1700 and 1900, Europe’s population increased from about 100 million to over 400 million.[53] Altogether, the areas populated by people of European descent comprised 36% of the world's population in 1900.[54]

Population growth in the West became more rapid after the introduction of vaccination and other improvements in medicine and sanitation.[55] Improved material conditions led to the population of Britain increasing from 10 million to 40 million in the 19th century.[56] The population of the United Kingdom reached 60 million in 2006.[57] The United States saw its population grow from around 5.3 million in 1800 to 106 million in 1920, exceeding 307 million in 2010.[58]

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).[59][60] After the collapse of the Soviet Union, Russia's population declined significantly – from 150 million in 1991 to 143 million in 2012[61] – but by 2013 this decline appeared to have halted.[62]

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,[63] 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;[64] today, India, Pakistan and Bangladesh are collectively home to about 1.5 billion people.[65] Java had about 5 million inhabitants in 1815; its present-day successor, Indonesia, now has a population of over 140 million.[66] Mexico's population grew from 13.6 million in 1900 to about 112 million in 2010.[67][68] Between the 1920s and 2000s, Kenya's population grew from 2.9 million to 37 million.[69]

Milestones by the billions

World population milestones (USCB estimates)[70]
Population
(in billions)
1 2 3 4 5 6 7 8 9
Year 1804 1927 1959 1974 1987 1999 2011 2024 2037
Years elapsed between milestones 123 32 15 13 12 12 13 13

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.[71] 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.[70] The United Nations, however, estimated that the world population reached seven billion in October 2011.[7][8][9]

According to current projections, the global population will reach eight billion by 2024, and will likely reach around nine billion by 2037. Alternative scenarios for 2050 range from a low of 7.4 billion to a high of more than 10.6 billion.[72] 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.[72] 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.[13][73]

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 celebrate, the "Day of 5 Billion" on July 11, 1987, and the "Day of 6 Billion" on October 12, 1999. The "Day of 7 Billion" was declared by the Population Division of the United Nations to be October 31, 2011.[74]

Global demographics

2012 map showing average life expectancy by country in years. In 2012, the World Health Organization estimated the average global life expectancy as 70.5 years.[75]
  80+
  77.5+
  75+
  72.5+
  70+
  67.5+
  65+
  60+
  55+
  50+
  45+
  40+
  less than 40

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 gender imbalances evident in the Indian and Chinese populations.[76][77] 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.[76] The median age of the world's population was estimated to be 29.7 years in 2014,[78] and is expected to rise to 37.9 years by 2050.[79]

According to the World Health Organization, the global average life expectancy is 70.5 years as of 2012, with women living an average of 73 years and men approximately 68 years.[75] In 2010, the global fertility rate was estimated at 2.52 children per woman.[73] 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).[80]

The nominal 2013 gross world product was estimated at US$74.31 trillion by the CIA, giving an annual global per capita figure of around US$10,500.[81] Around 1.29 billion people (18.4% of the world population) live in extreme poverty, subsisting on less than US$1.25 per day;[82] approximately 870 million people (12.25%) are undernourished.[83] 83% of the world's over-15s are considered literate.[76] In June 2014, there were around 3.03 billion global Internet users, constituting 42.3% of the world population.[84]

The Han Chinese are the world's largest single ethnic group, constituting over 19% of the global population in 2011.[85] 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%).[76] The world's largest religion is Christianity, whose adherents account for 33.35% of the global population; Islam is the second-largest religion, accounting for 22.43%, and Hinduism the third, accounting for 13.78%.[76] In 2005, around 16% of the global population were reported to be non-religious.[86]

Largest populations by country

A map of world population in 2014
10 most populous countries
Rank Country / Territory Population Date Approx. % of world
population
Source
1  China[note 2] 1,426,467,320 17.5% 10 Nov 2024 [87]
2  India 1,409,100,625 17.3% 10 Nov 2024 [88]
3  United States 337,142,710 4.14% 10 Nov 2024 [89]
4  Indonesia 252,164,800 July 1, 2014 3.1% [90]
5  Brazil 218,400,331 2.68% 10 Nov 2024 [91]
6  Pakistan 239,335,965 2.94% 10 Nov 2024 [92]
7  Nigeria 173,615,000 January 1, 2014 2.13% [93]
8  Bangladesh 177,840,478 2.18% 10 Nov 2024 [94]
9  Russia 146,068,400 June 1, 2014 1.79% [95]
10  Japan 127,130,000 August 1, 2014 1.56% [96]

Approximately 4.231 billion people live in these ten countries, representing around 51% of the world's population as of August 2014. Approximately 3.7 billion people, or half of the world population, live in the six most populous countries.[97]

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.

Population density (people per km2) map of the world in 1994. Red and pink areas denote regions of highest population density.
10 most densely populated countries / regions (with population above 1 million)
Rank Country / Region Population Area (km2) Density
(Pop. per km2)
1  Singapore 5,399,200 710 7605
2  Bahrain 1,234,571 750 1646
3  Bangladesh 149,772,364 147,570 1101
4  Taiwan 23,361,147 36,190 645
5  Mauritius 1,257,900 2,040 617
6  South Korea 50,219,669 99,538 505
7  Lebanon 4,822,000 10,452 461
8  Netherlands[98] 16,911,719 41,526 407
9  Rwanda 10,537,222 26,338 400
10  Haiti 10,413,211 27,065 385
Countries / regions ranking highly in terms of both total population (more than 15 million people) and population density (more than 250 people per square kilometer):
Country / Region Population Area (km2) Density
(Pop. per km2)
Notes
 India Template:Popareadens Growing country
 Bangladesh 149,772,364 147,570 1101 Slowly growing country
 Japan 127,180,000 377,873 337 Declining in population[99]
 Philippines 98,698,000 300,076 329 Growing country
 Vietnam 90,388,000 331,689 268 Growing country
 United Kingdom 63,705,000 243,610 262 Slowly growing country
 South Korea 50,219,669 99,538 505 Slowly growing country[100]
 Taiwan 23,361,147 36,190 645 Steady in population
 Sri Lanka 20,328,597 65,610 309 Slowly growing country
 Netherlands 16,848,208 41,526 406 Steady in population[101]

Fluctuation

Estimates of population evolution in different continents between 1950 and 2050, according to the United Nations. The vertical axis is logarithmic and is in millions of people.

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. This increase was due to a number of factors, 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.[102][103][104]

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),[105] 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.[106]

A world map showing global variations in fertility rate per woman, according to the CIA World Factbook's 2015 data.

In some countries, there is negative population growth (i.e. a net decrease in population over time), especially in Europe – this is mainly due to low fertility rates. During the 2010s, Japan and some countries in Europe began to encounter negative population growth, due to sub-replacement fertility rates.[99]

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.[107] 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.[108] 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.[109]

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,[110] while the USCB asserted that this occurred in March 2012.[111] 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 March 14, 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.

UN (medium variant – 2012 revision) and US Census Bureau (June 2015) estimates[112][113]
Year UN est.
(millions)
Difference USCB est.
(millions)
Difference
2005 6,514 6,474
2010 6,916 402 6,866 392
2015 7,324 408 7,253 387
2020 7,717 393 7,631 378
2025 8,083 366 7,987 356
2030 8,425 342 8,316 329
2035 8,743 318 8,619 303
2040 9,039 296 8,897 278
2045 9,308 269 9,150 253
2050 9,551 243 9,376 227
UN 2012 estimates and medium variant projections (in millions)[112]
Year World Asia Africa Europe Latin America/Caribbean Northern America Oceania
2010 6,916 4,165 (60.2%) 1,031 (14.9%) 740 (10.7%) 596 (8.6%) 347 (5.0%) 37 (0.5%)
2015 7,324 4,385 (59.9%) 1,166 (15.9%) 743 (10.1%) 630 (8.6%) 361 (4.9%) 39 (0.5%)
2020 7,717 4,582 (59.4%) 1,312 (17.0%) 744 (9.6%) 662 (8.6%) 376 (4.9%) 42 (0.5%)
2025 8,083 4,749 (58.8%) 1,468 (18.2%) 741 (10.1%) 691 (9.2%) 390 (4.8%) 45 (0.6%)
2030 8,425 4,887 (58.0%) 1,634 (19.4%) 736 (8.7%) 717 (8.5%) 403 (4.8%) 47 (0.6%)
2035 8,743 4,997 (57.2%) 1,812 (20.7%) 730 (8.3%) 739 (8.5%) 415 (4.8%) 50 (0.6%)
2040 9,039 5,080 (56.2%) 1,999 (22.1%) 724 (8.0%) 757 (8.4%) 426 (4.8%) 52 (0.6%)
2045 9,308 5,136 (55.2%) 2,194 (23.6%) 717 (7.7%) 771 (8.3%) 436 (4.7%) 55 (0.6%)
2050 9,551 5,164 (54.1%) 2,393 (25.1%) 709 (7.4%) 782 (8.2%) 446 (4.7%) 57 (0.6%)
2055 9,766 5,168 (52.9%) 2,595 (26.6%) 700 (7.2%) 788 (8.1%) 456 (4.7%) 59 (0.6%)
2060 9,957 5,152 (51.7%) 2,797 (28.1%) 691 (6.9%) 791 (7.9%) 465 (4.7%) 61 (0.6%)
2065 10,127 5,120 (50.6%) 2,998 (29.6%) 681 (6.7%) 791 (7.8%) 474 (4.7%) 63 (0.6%)
2070 10,277 5,075 (49.4%) 3,195 (31.1%) 673 (6.5%) 788 (7.6%) 482 (4.7%) 64 (0.6%)
2075 10,409 5,019 (48.2%) 3,387 (32.5%) 665 (6.4%) 783 (7.5%) 490 (4.7%) 66 (0.6%)
2080 10,524 4,957 (47.1%) 3,570 (33.9%) 659 (6.3%) 776 (7.4%) 496 (4.7%) 67 (0.6%)
2085 10,626 4,894 (46.1%) 3,742 (35.2%) 653 (6.1%) 767 (7.2%) 502 (4.7%) 68 (0.6%)
2090 10,717 4,833 (45.1%) 3,903 (36.4%) 649 (6.1%) 757 (7.1%) 506 (4.7%) 69 (0.6%)
2095 10,794 4,773 (44.2%) 4,051 (37.6%) 644 (6.0%) 747 (6.9%) 510 (4.7%) 69 (0.6%)
2100 10,854 4,712 (43.4%) 4,185 (38.6%) 639 (5.9%) 736 (6.8%) 513 (4.7%) 70 (0.6%)

Population growth by region

The table below shows historical and predicted regional population figures in millions.[110][114][115] The availability of historical population figures varies by region.

World historical and predicted populations (in millions)[116][117]
Region 1500 1600 1700 1750 1800 1850 1900 1950 1999 2008 2010 2012 2050 2150
World 458 580 682 791 978 1,262 1,650 2,521 5,978 6,707 6,896 7,052 8,909 9,746
Africa 86 114 106 106 107 111 133 221 767 973 1,022 1,052 1,766 2,308
Asia 243 339 436 502 635 809 947 1,402 3,634 4,054 4,164 4,250 5,268 5,561
Europe 84 111 125 163 203 276 408 547 729 732 738 740 628 517
Latin America[Note 1] 39 10 10 16 24 38 74 167 511 577 590 603 809 912
Northern America[Note 1] 3 3 2 2 7 26 82 172 307 337 345 351 392 398
Oceania 3 3 3 2 2 2 6 13 30 34 37 38 46 51
World historical and predicted populations by percentage distribution[116][117]
Region 1500 1600 1700 1750 1800 1850 1900 1950 1999 2008 2010 2012 2050 2150
World 100 100 100 100 100 100 100 100 100 100 100 100 100 100
Africa 18.8 19.7 15.5 13.4 10.9 8.8 8.1 8.8 12.8 14.5 14.8 15.2 19.8 23.7
Asia 53.1 58.4 63.9 63.5 64.9 64.1 57.4 55.6 60.8 60.4 60.4 60.3 59.1 57.1
Europe 18.3 19.1 18.3 20.6 20.8 21.9 24.7 21.7 12.2 10.9 10.7 10.5 7.0 5.3
Latin America[Note 1] 8.5 1.7 1.5 2.0 2.5 3.0 4.5 6.6 8.5 8.6 8.6 8.6 9.1 9.4
Northern America[Note 1] 0.7 0.5 0.3 0.3 0.7 2.1 5.0 6.8 5.1 5.0 5.0 5.0 4.4 4.1
Oceania 0.7 0.5 0.4 0.3 0.2 0.2 0.4 0.5 0.5 0.5 0.5 0.5 0.5 0.5

Note: in the table below, the figures for North America only refer to post-European contact settlers, and not native populations from before European settlement.

Estimated world and regional populations at various dates (in millions)
Year World Africa Asia Europe Latin America[Note 1] Northern America[Note 1] Oceania Notes
70,000 BCE < 0.015 [118]
10,000 BCE 4 [119]
8000 BCE 5
6500 BCE 5
5000 BCE 5
4000 BCE 7
3000 BCE 14
2000 BCE 27
1000 BCE 50 7 33 9 [citation needed]
500 BCE 100 14 66 16
CE 1 200 23 141 28
1000 400 70 269 50 8 1 2
1750 791 106 502 163 16 2 2
1800 1,000 107 656 203 24 7 3
1850 1,262 111 809 276 38 26 2
1900 1,650 133 947 408 74 82 6
1950 2,519 221 1,398 547 167 172 12.8 [120]
1955 2,756 247 1,542 575 191 187 14.3
1960 2,982 277 1,674 601 209 204 15.9
1965 3,335 314 1,899 634 250 219 17.6
1970 3,692 357 2,143 656 285 232 19.4
1975 4,068 408 2,397 675 322 243 21.5
1980 4,435 470 2,632 692 361 256 22.8
1985 4,831 542 2,887 706 401 269 24.7
1990 5,263 622 3,168 721 441 283 26.7
1995 5,674 707 3,430 727 481 299 28.9
2000 6,070 796 3,680 728 520 316 31.0
2005 6,454 888 3,917 725 558 332 32.9
2010 6,972 1,022 4,252 732 580 351 35.6
  1. ^ a b c d e f Northern America comprises the northern-most countries and territories of North America: Canada, the United States, Greenland, Bermuda, and St. Pierre and Miquelon. Latin America comprises Mexico, Central America, the Caribbean and South America.

Mathematical approximations

In 1975, Sebastian von Hoerner proposed a formula for population growth which represented hyperbolic growth with an infinite population in 2025.[121] 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.[122] The transition from hyperbolic growth to slower rates of growth is related to the demographic transition.

According to the Russian demographer Sergey Kapitsa,[123] the world population grew between 67,000 BCE and 1965 according to the following formula:

where

  • 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 CE, each doubling took roughly half as long as the previous doubling, fitting the hyperbolic growth model mentioned above. However, after 2025 it is unlikely that there will be another doubling of the global population in the 21st century.[124]

Historic chart showing the periods of time the world population has taken to double, from 1700 to 2000.
Starting at 500 million
Population
(in billions)
0.5 1 2 4 8
Year 1500 1804 1927 1974 2025
Years elapsed 304 123 47 51
Starting at 375 million
Population
(in billions)
0.375 0.75 1.5 3 6
Year 1171 1715 1881 1960 1999
Years elapsed 544 166 79 39

Overpopulation

Predictions of scarcity

Greater Los Angeles lies on a coastal mediterranean savannah with a small watershed that is able to support at most one million people on its own water; as of 2015, the area has a population of over 18 million. Researchers predict that similar cases of resource scarcity will grow more common as the world population increases.[125]

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. The essay was written to refute what Malthus 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.[126]

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%.[127] 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.[128] However, neo-Malthusians point out that the energy for the Green Revolution was provided by fossil fuels, 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.[129]

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.[130]

Graph of the global human population from 10,000 BCE to 2000 CE, from the US Census Bureau. The graph shows the extremely rapid growth in the world population that has taken place since the 18th century.
The human population has been growing exponentially since the mid-1800s.

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),[131] global population growth,[132] the effects of climate change,[133] the loss of agricultural land to residential and industrial development,[134][135] and growing consumer demand in the population centres of China and India.[136][137] Food riots subsequently occurred in some countries.[138][139] 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.[140][141]

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.[142] 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.[125][143] According to a 2009 report by the United Nations Food and Agriculture Organisation (FAO), the world will have to produce 70% more food by 2050 to feed a projected extra 2.3 billion people.[144]

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.[145] The 2009 FAO estimates showed an even more dramatic increase, to 1.02 billion.[146]

Environmental impacts

Illegal slash-and-burn agriculture in Madagascar, 2010.

A number of scientists have argued that the current global population expansion and accompanying increase in resource consumption threatens the world's ecosystem, as well as straining humanity's ability to feed itself.[147][148] The InterAcademy Panel Statement on Population Growth, which was ratified by 58 member national academies in 1994, called the growth in human numbers "unprecedented", and stated that many environmental problems, such as rising levels of atmospheric carbon dioxide, global warming, and pollution, were aggravated by the population expansion.[149] Indeed, some analysts claim that overpopulation's most serious impact is its effect on the environment.[18] 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.

Population control

India is anticipated to overtake China as the world's most populous country by 2022.

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,[150] with religious organizations such as the Roman Catholic Church explicitly opposing any intervention in the human reproductive process.[151]

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."[152] 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.[153]

Overpopulation as a myth

The Population Research Institute (PRI), an anti-abortion, anti-contraception advocacy group, has criticised predictions of overpopulation and attendant resource scarcity, with some describing overpopulation as a myth.[154] The PRI argues that advances in agricultural, medical, and industrial technology have allowed global economic productivity to keep pace with rising populations despite Malthusian predictions to the contrary. PRI further says that family sizes are naturally declining worldwide due to higher living standards, increased availability of contraception and better economic opportunities for women. However, other commentators have described PRI's arguments on overpopulation as deceptive.[155][156][157]

Number of humans who have ever lived

An estimate of the total number of humans who have ever lived was prepared by Carl Haub of the nonprofit Population Reference Bureau in 1995, and was subsequently updated in 2002 and 2011; the 2011 figure was approximately 107 billion.[20][21][158] 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".[21] Several other scholarly estimates published in the first decade of the 21st century give figures ranging from approximately 100 billion to 115 billion.

Estimation methodologies

An accurate estimate of the number of humans who have ever lived is difficult to produce for numerous reasons. Firstly, the set of specific characteristics that define a "human" is a matter of definition, and it is open to debate which members of early Homo sapiens and earlier or related species of Homo to include in the estimate (see also Sorites paradox). Even if the scientific community reached a broad 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, due to the scarcity of fossil evidence. However, the very small size of the world population in prehistoric times (as compared to its current size) makes this uncertainty of limited importance.

More importantly, 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.[159] Thus, there is a significant margin of error when estimating ancient global populations.

Another critical factor for such an estimate is life expectancy, which depends significantly on infant mortality rates; these figures are very difficult to estimate for ancient times due to a lack of accurate records. Haub's estimates suggest that around 40% of those who have ever lived did not survive beyond their first birthday.[21] Haub also stated that "life expectancy at birth probably averaged only about ten years for most of human history".[21]

See also

30em

Notes

  1. ^ 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.
  2. ^ Figure refers to Mainland China only. It excludes Taiwan and the special administrative regions of Hong Kong and Macau.

References

  1. ^ a b "UN projects world population to reach 8.5 billion by 2030, driven by growth in developing countries". United Nations Department of Economic and Social Affairs. July 29, 2013. Retrieved July 30, 2015.
  2. ^ 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.
  3. ^ "Exponential Population Growth". Kivu. May 10, 2012. Retrieved July 22, 2013.
  4. ^ "World Population Prospects, 2012 revision (697 million births from 1985–1990)". United Nations. 2012. Retrieved May 11, 2015.[dead link]
  5. ^ "Annual number of births – World". United Nations Population Division. 2011. Retrieved March 27, 2015.
  6. ^ "World Population estimates by the US Census Bureau". USCB. Retrieved May 22, 2012.[dead link]
  7. ^ a b "Population seven billion: UN sets out challenges". BBC News. October 26, 2011. Retrieved October 27, 2011.
  8. ^ a b Coleman, Jasmine (October 31, 2011). "World's 'seven billionth baby' is born". The Guardian. London. Retrieved October 31, 2011.
  9. ^ a b "7 billion people is a 'serious challenge". UPI. October 31, 2011. Retrieved November 9, 2011.
  10. ^ "World Population Clock – Worldometers". Worldometers.info. Retrieved April 12, 2012.
  11. ^ "World Population Prospects, the 2012 Revision – "Low variant" and "High variant" values". UN. 2012. Retrieved June 15, 2013.
  12. ^ "World population projected to reach 9.6 billion by 2050 – UN report". UN News Centre. June 14, 2013. Retrieved June 16, 2013.
  13. ^ a b "Key Findings". Long-Range Population Projections (PDF). New York: United Nations: Department of Economic and Social Affairs. 2003. Retrieved July 3, 2010. {{cite book}}: |work= ignored (help)
  14. ^ "A model predicts that the world's populations will stop growing in 2050". ScienceDaily.com. April 4, 2013. Retrieved June 3, 2013.
  15. ^ Carrington, Damien (September 18, 2014). "World population to hit 11bn in 2100 – with 70% chance of continuous rise". The Guardian. Retrieved September 21, 2014.
  16. ^ Template:Cite doi/10.1126.2Fscience.1257469
  17. ^ Peter P. Rogers; Kazi F. Jalal; John A. Boyd (2008). An Introduction To Sustainable Development. Earthscan via Google Books. p. 53. {{cite book}}: Unknown parameter |last-author-amp= ignored (|name-list-style= suggested) (help)
  18. ^ a b "Overpopulation's Real Victim Will Be the Environment". TIME. October 26, 2011. Retrieved February 18, 2013.
  19. ^ Zehner, Ozzie (2012). Green Illusions. Lincoln and London: University of Nebraska Press. pp. 187–331.
  20. ^ a b Curtin, Ciara (March 1, 2007). "Fact or Fiction?: Living People Outnumber the Dead". Scientific American. 297 (3). Scientific American, Inc. (published September 2007): 126. doi:10.1038/scientificamerican0907-126. Retrieved August 4, 2008. Note: text of paper publication slightly different from text of on-line publication
  21. ^ a b c d e Haub, Carl (November–December 2002). "How Many People Have Ever Lived on Earth?" (PDF). Population Today. 30 (8). Population Reference Bureau: 3–4. Retrieved August 4, 2008.
  22. ^ "CO2 Emissions from Fuel Combustion: Population 1971–2008" (PDF). IEA (OECD/World Bank). pp. 83–85. Retrieved July 9, 2013.
  23. ^ "World Population Prospects: The 2010 Revision Population Database". United Nations. April 15, 2011. Retrieved April 21, 2012.
  24. ^ a b "Antarctica". CIA World Factbook. June 19, 2014. Retrieved March 18, 2015.
  25. ^ Excluding its Special Administrative Regions (SARs) of Hong Kong and Macau.
  26. ^ Including Central America and the Caribbean.
  27. ^ "Life Expectancy in the Paleolithic". PaleoDiet.com. 2010. Retrieved July 10, 2013.
  28. ^ Luc-Normand Tellier (2009). Urban world history: an economic and geographical perspective. PUQ via Google Books. p. 26. ISBN 2-7605-1588-5.
  29. ^ Dr. Kenneth W. Harl (1998). "Population estimates of the Roman Empire". Tulane.edu. Retrieved December 8, 2012.
  30. ^ "Plague, Plague Information, Black Death Facts, News, Photos". National Geographic. Retrieved November 3, 2008.
  31. ^ "History of Europe – Demographic and agricultural growth". Encyclopædia Britannica. 2012. Retrieved December 17, 2012.
  32. ^ "Historical Estimates of World Population". Census.gov. Retrieved November 3, 2008.
  33. ^ Jay, Peter (July 17, 2000). "A Distant Mirror". TIME Europe. 156 (3). Archived from the original on July 25, 2008. Retrieved August 9, 2014.
  34. ^ Horst R. Thieme (2003). Mathematics in population biology. Princeton University Press via Google Books. p. 285. ISBN 0-691-09291-5.
  35. ^ Graziella Caselli; Gillaume Wunsch; Jacques Vallin (2005). Demography: Analysis and Synthesis, Four Volume Set: A Treatise in Population. Academic Press via Google Books. p. 34. ISBN 0-12-765660-X. {{cite book}}: Unknown parameter |last-author-amp= ignored (|name-list-style= suggested) (help)
  36. ^ "Qing China's Internal Crisis: Land Shortage, Famine, Rural Poverty". Columbia University: Asia for Educators. 2009. Retrieved July 9, 2013.
  37. ^ "History of Europe – Demographics". Encyclopædia Britannica. Retrieved July 9, 2013.
  38. ^ "China's Population: Readings and Maps". Columbia University: East Asian Curriculum Project. Retrieved December 18, 2012.
  39. ^ "The Columbian Exchange". University of North Carolina. Retrieved December 18, 2012.
  40. ^ "Super-Sized Cassava Plants May Help Fight Hunger In Africa". Ohio State University. May 24, 2006. Retrieved July 9, 2013.
  41. ^ James Brabazon (2000). Albert Schweitzer: a biography. Syracuse University Press via Google Books. p. 242. ISBN 0-8156-0675-3.
  42. ^ S. Chandrasekhar (2013). Infant Mortality, Population Growth and Family Planning in India: An Essay on Population Problems and International Tensions. Routledge. pp. 24–7. ISBN 1136883061.
  43. ^ Maheshwari, Shriram (1996). The Census Administration Under the Raj and After. Concept Publishing Company. p. 14. ISBN 817022585X.
  44. ^ "Microchronology and Demographic Evidence Relating to the Size of Pre-Columbian North American Indian Populations". Science. June 16, 1995. Retrieved July 9, 2013.
  45. ^ Arthur C. Aufderheide; Conrado Rodríguez-Martín; Odin Langsjoen (1998). The Cambridge encyclopedia of human paleopathology. Cambridge University Press via Google Books. p. 205. ISBN 0-521-55203-6. {{cite book}}: Unknown parameter |last-author-amp= ignored (|name-list-style= suggested) (help)
  46. ^ "The Story Of... Smallpox – and other Deadly Eurasian Germs". Public Broadcasting Service. 2005. Retrieved April 24, 2013.
  47. ^ Austin Alchon, Suzanne (2003). A pest in the land: new world epidemics in a global perspective. University of New Mexico Press. p. 31. ISBN 0-8263-2871-7.
  48. ^ "World Demographics Profile 2012". Index Mundi. Retrieved May 22, 2012.
  49. ^ "By 2050, 70% of the world's population will be urban. Is that a good thing?". Fast Co. Design. 2012. Retrieved May 1, 2012.
  50. ^ Population crises and cycles in history – A review by Claire Russell and W.M.S. Russell, Vicnet.net.au, retrieved March 26, 2015
  51. ^ Buer, Mabel C. (1926). Health, Wealth and Population in the Early Days of the Industrial Revolution. London: George Routledge & Sons. p. 30. ISBN 0-415-38218-1.
  52. ^ "The Foundling Hospital". BBC History. October 5, 2012. Retrieved April 22, 2013.
  53. ^ "Modernization – Population Change". Encyclopædia Britannica. Retrieved February 6, 2013.
  54. ^ Graziella Caselli; Gillaume Wunsch; Jacques Vallin (2005). Demography: Analysis and Synthesis, Four Volume Set: A Treatise in Population. Academic Press via Google Books. p. 42. ISBN 0-12-765660-X. {{cite book}}: Unknown parameter |last-author-amp= ignored (|name-list-style= suggested) (help)
  55. ^ "Victorian Medicine – From Fluke to Theory". BBC History. February 1, 2002. Retrieved February 17, 2013.
  56. ^ "A portrait of Britain in 2031". The Independent. October 24, 2007. Retrieved February 17, 2013.
  57. ^ "UK population breaks through 60m". BBC News. August 24, 2006. Retrieved April 14, 2012.
  58. ^ "US population through history". About.com. Retrieved April 14, 2012.
  59. ^ Jay Winter, Emmanuel Sivan (2000). War and Remembrance in the Twentieth Century. Cambridge University Press. p. 64. ISBN 0521794366.
  60. ^ Mark Harrison (2002). Accounting for War: Soviet Production, Employment, and the Defence Burden, 1940–1945. Cambridge University Press via Google Books. p. 167. ISBN 0-521-89424-7.
  61. ^ "Vladimir Putin vows to reverse Russian population decline". The Daily Telegraph. February 13, 2012. Retrieved April 13, 2012.
  62. ^ "Russia's Population Decline Said To Have 'Stopped'". Radio Free Europe. May 27, 2013. Retrieved June 15, 2013.
  63. ^ "China's demographic evolution 1850–1953 reconsidered". The China Quarterly. JSTOR. 1978. Retrieved April 13, 2012.
  64. ^ "Reintegrating India with the World Economy" (PDF). Peterson Institute for International Economics. 2003. Retrieved November 8, 2012.
  65. ^ "India". CIA World Factbook. July 2012. Retrieved October 21, 2012.
  66. ^ "Java (island, Indonesia)". Encyclopædia Britannica. Retrieved July 7, 2013.
  67. ^ Jorge Durand (March 2004). "From Traitors to Heroes: 100 Years of Mexican Migration Policies". University of Guadalajara. Retrieved July 16, 2013.
  68. ^ "Population and Housing Census: Mexico 2010" (PDF). University of Minnesota. March 3, 2011. Retrieved July 16, 2013.
  69. ^ Gunnar Heinsohn (January 7, 2008). "Kenya's Violence: Exploding population". The New York Times. Retrieved July 7, 2013.
  70. ^ a b "U.S. Census Bureau – World POPClock Projection". July 2013. The number on this page is automatically updated daily.
  71. ^ "The World at Six Billion: Introduction" (PDF). United Nations. 1999. Retrieved July 14, 2013.
  72. ^ a b
  73. ^ a b "Total fertility estimates, 1950–2010". UN Population Division. April 2011. Retrieved June 14, 2012.
  74. ^ "World Population Prospects, the 2008 Revision – Frequently Asked Questions". Population Division of the Department of Economic and Social Affairs of the United Nations Secretariat. November 10, 2010. Retrieved March 26, 2015.
  75. ^ a b "World Health Statistics 2014: Large gains in life expectancy". World Health Organization. May 15, 2014. Retrieved March 14, 2015.
  76. ^ a b c d e "World Demographics Profile 2011". Index Mundi. Retrieved November 18, 2011.
  77. ^ "Sex-ratio imbalance in Asia: Trends, consequences and policy responses" (PDF). UNFPA. 2007. Retrieved May 20, 2012.
  78. ^ "World Demographics Profile 2014". Index Mundi. Retrieved October 4, 2014.
  79. ^ Janneh, Abdoulie (April 2012). "General debate on national experience in population matters: adolescents and youth" (PDF). United Nations Economic Commission for Africa. Retrieved February 19, 2014.
  80. ^ "Global weight gain more damaging than rising numbers". BBC. June 18, 2012. Retrieved February 12, 2013.
  81. ^ "World". CIA World Factbook. 2015. Retrieved January 17, 2015.
  82. ^ "What It Will Take to 'Graduate' 1.2 Billion People Out of Extreme Poverty". Huffington Post. April 4, 2012. Retrieved April 26, 2012.
  83. ^ Food and Agriculture Organization of the United Nations, The State of Food Insecurity in the World. WorldHunger.org. 2012. Retrieved April 26, 2012.
  84. ^ "Statistics". Internet World Stats. June 30, 2014. Retrieved March 5, 2015.
  85. ^ "World’s Most Typical Person: Han Chinese Man". Wall Street Journal. March 4, 2011. Retrieved November 18, 2011.
  86. ^ Religions by adherents. Adherents.com. 2005 data. Retrieved December 19, 2011.
  87. ^ "Chinese Official Population Clock (updated daily, in Chinese)". CPDRC.org.cn. Retrieved May 22, 2012.
  88. ^ "Official population clock". IndiaStat.com. Retrieved October 4, 2014.
  89. ^ "United States Official Population Clock (updated daily)". USCB. Retrieved May 22, 2012.
  90. ^ "Penduduk Indonesia Tengah Tahun menurut Jenis Kelamin". BI.go.id. Retrieved March 21, 2015.
  91. ^ "Official population clock". IBGE.gov.br. Retrieved October 4, 2014.
  92. ^ "Official Pakistani Population Clock". Population Census Organization of Pakistan. Retrieved November 15, 2012.
  93. ^ "Population, total". World Bank. 2014. Retrieved March 21, 2015.
  94. ^ "Official population clock". BBS.gov.bd. Retrieved October 4, 2014.
  95. ^ "Official estimate (including Crimea and Sevastopol)". GKS.ru. Retrieved March 21, 2015.
  96. ^ "Japan population". Official Japan Statistics Bureau. Retrieved October 4, 2014.
  97. ^ Hackett, C. (July 11, 2014). "Which six countries hold half the world's population?". Pew Research Center. Retrieved March 13, 2015.
  98. ^ "Official population clock". CBS.nl. Retrieved November 14, 2014.
  99. ^ a b Demetriou, Danielle (April 17, 2013). "Japan's population suffers biggest fall in history". Daily Telegraph. London. Retrieved July 22, 2013.
  100. ^ "Aging to challenge South Korea's economic transformation". CNBC. October 29, 2013. Retrieved March 21, 2015.
  101. ^ "Fewer people move to Holland as the population growth slows". DutchNews.nl. February 7, 2013. Retrieved July 23, 2013.
  102. ^ "The limits of a Green Revolution?". BBC News. March 29, 2007. Retrieved August 1, 2010.
  103. ^ "The Real Green Revolution". Energybulletin.net. Archived from the original on June 23, 2008. Retrieved August 1, 2010.
  104. ^ "World Population to 2300" (PDF). United Nations Department of Economic and Social Affairs. 2004. Retrieved June 16, 2013.
  105. ^ "International Programs". USCB. January 7, 2009. Retrieved December 16, 2012.
  106. ^ Ron Nielsen (2006). The Little Green Handbook. New York: Picador. ISBN 0-312-42581-3.
  107. ^ "2006 report highlights" (PDF). United Nations. Retrieved August 1, 2010.
  108. ^ "UN population estimates and projections, database query, August 2009". United Nations. March 11, 2009. Retrieved August 1, 2010.
  109. ^ Randers, Jorgen (2012). 2052: A Global Forecast for the Next Forty Years. Vermont: Chelsea Green Publishing. p. 62.
  110. ^ a b "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 June 20, 2013.
  111. ^ "Notes on the World POPClock and World Vital Events". US Census Bureau. Retrieved February 12, 2013.
  112. ^ a b "World Population Prospects: The 2012 Revision" (XLS). Population Division of the Department of Economic and Social Affairs of the United Nations Secretariat. June 2013. Retrieved August 7, 2013.
  113. ^ "World Population – Total Midyear Population for the World: 1950–2050". Census.gov. December 2013. Retrieved June 27, 2015.
  114. ^ "The World at Six Billion". United Nations. October 12, 1999. Retrieved August 1, 2010.
  115. ^ "Population Growth over Human History". University of Michigan. January 4, 2006. Retrieved March 9, 2013.
  116. ^ a b Figures include the former Soviet countries in Europe. Caselli, Graziella; Gillaume Wunsch; Jacques Vallin (December 20, 2005). Demography: Analysis and Synthesis, Four Volume Set: A Treatise in Population. Academic Press. p. 42. ISBN 978-0-12-765660-1.
  117. ^ a b "UN report – 2004 data" (PDF). Retrieved August 1, 2010.
  118. ^ 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. April 30, 2013. Retrieved March 21, 2015.
  119. ^ 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" in The Quarterly Journal of Economics 108(3): 681–716.
  120. ^ An approximation based on figures from different sources as listed at the US Census Bureau's Total Midyear Population for the World: 1950-2050
  121. ^ Sebastien von Hoerner (1975). "Population Explosion and Interstellar Expansion". Journal of the British Interplanetary Society (28): 691–712.
  122. ^ 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".
  123. ^ Kapitsa, Sergei P. (1996). "The phenomenological theory of world population growth". Physics-Uspekhi. 39 (1): 57–71. Retrieved July 26, 2013.
  124. ^ Lutz, Wolfgang; Sanderson, Warren; Scherbov, Sergei (June 19, 1997). "Doubling of world population unlikely". Nature. 387 (6635): 803–805. doi:10.1038/42935. PMID 9194559. Retrieved October 23, 2012.
  125. ^ a b "World faces 'perfect storm' of problems by 2030, chief scientist to warn". The Guardian. March 18, 2009. Retrieved February 18, 2013.
  126. ^ Jowit, Juliette (October 23, 2011). "Paul Ehrlich, a prophet of global population doom who is gloomier than ever". The Guardian. London. Retrieved July 22, 2013.
  127. ^ Kindall, Henery W; Pimentel, David (May 1994). "Constraints on the Expansion of the Global Food Supply". Ambio. 23 (3). {{cite journal}}: Unknown parameter |last-author-amp= ignored (|name-list-style= suggested) (help)
  128. ^ "The limits of a Green Revolution?". BBC News. March 29, 2007. Retrieved February 18, 2013.
  129. ^ "Host Plant Resistance and Conservation of Genetic Diversity". Radcliffe's IPM World Textbook. University of Minnesota. March 2013. Retrieved July 20, 2013.
  130. ^ 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.
  131. ^ "The global grain bubble". Christian Science Monitor. January 18, 2008. Retrieved February 18, 2013.
  132. ^ James Randerson, science correspondent (March 7, 2008). "Food crisis will take hold before climate change, warns chief scientist". The Guardian. London. Retrieved February 18, 2013. {{cite news}}: |author= has generic name (help)
  133. ^ John Vidal, environment editor (November 3, 2007). "Global food crisis looms as climate change and fuel shortages bite". The Guardian. London. Retrieved February 18, 2013. {{cite news}}: |author= has generic name (help)
  134. ^ Walsoft (February 22, 2008). "Experts: Global Food Shortages Could 'Continue for Decades'". Marketoracle.co.uk. Retrieved February 18, 2013.
  135. ^ Moya K. Mason. "Has Urbanization Caused a Loss to Agricultural Land?". Moyak.com. Retrieved July 9, 2013.
  136. ^ Walt, Vivienne (February 27, 2008). "The World's Growing Food-Price Crisis". Time. Retrieved February 18, 2013.
  137. ^ "The cost of food: Facts and figures". BBC. October 16, 2008. Retrieved February 18, 2013.
  138. ^ Julian Borger (February 26, 2008). "Feed the world? We are fighting a losing battle, UN admits". The Guardian. London. Retrieved February 18, 2013.
  139. ^ Buchanan, Emily (April 22, 2008). "Assessing the global food crisis". BBC News. Retrieved April 6, 2010.
  140. ^ "Half of all food 'wasted' report claims". BBC. January 10, 2013. Retrieved January 10, 2013.
  141. ^ "Oil shock could push world food prices higher". CNN Money. March 3, 2011. Retrieved February 18, 2013.
  142. ^ 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 0-7923-6351-5.
  143. ^ "Global crisis 'to strike by 2030". BBC News. March 19, 2009. Retrieved February 18, 2013.
  144. ^ "Global food production will have to increase 70% for additional 2.3 billion people by 2050". Finfacts.com. September 24, 2009. Retrieved February 18, 2013.
  145. ^ "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 December 8, 2012.
  146. ^ "One sixth of humanity undernourished – more than ever before". Food and Agriculture Organization of the United Nations. 2009. Retrieved December 8, 2012.
  147. ^ "Ecological Debt Day". Retrieved February 18, 2013.
  148. ^ "Planetary Boundaries: Specials". Nature. September 23, 2009. Retrieved February 18, 2013.
  149. ^ "IAP (login required)". InterAcademies.net. Retrieved February 18, 2013.
  150. ^ 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. June 15, 2012. Retrieved August 29, 2012.
  151. ^ "Fighting poverty to build peace". Vatican. January 1, 2009. Retrieved October 24, 2011.
  152. ^ Zehmer, Ozzie (2012). Green lllusions. Lincoln and London: University of Nebraska. p. 188.
  153. ^ Connelly, Matthew (2008). Fatal Misconception: The Struggle to Control World Population. Harvard University Press via Google Books.
  154. ^ "Debunking the Myth of Overpopulation". Population Research Institute. 2013. Retrieved February 19, 2014.
  155. ^ "IAP Statement on Population and Consumption". InterAcademy Panel: The Global Network of Science Academies (IAP). June 14, 2012. Retrieved March 13, 2015.
  156. ^ "A Response to Critics of Family Planning Programs". Guttmacher.org. March 1, 2009. Retrieved November 18, 2014.
  157. ^ "Global Environment Outlook – Environment for the future we want" (PDF). UNEP. May 2012. Retrieved November 18, 2014.
  158. ^ Haub, Carl (October 2011). "How Many People Have Ever Lived on Earth?". Population Reference Bureau. Retrieved April 29, 2013.
  159. ^ Kuhrt, A. (1995). The Ancient Near East, c. 3000–330 BCE. Vol. 2. London: Routledge. p. 695.
Further reading
Organizations
Statistics and maps
Population clocks