1

World population
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World population estimates from 1800 to 2100, based on UN 2010 projections (red, orange,
green) and US Census Bureau historical estimates (black). Actual recorded population
figures are 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.
The world population is the total number of living humans on Earth. As of today, it is
estimated to number 7.08 billion by the United States Census Bureau (USCB).
[1]
The USCB
estimates that the world population exceeded 7 billion on March 12, 2012.
[2]
According to a
separate estimate by the United Nations Population Fund, it reached this milestone on
October 31, 2011.
[3][4][5]

The world population has experienced continuous growth since the end of the Great Famine
and the Black Death in 1350, when it stood at around 370 million.
[6]
The highest rates of
growth global population increases above 1.8% per year were seen briefly during the
1950s, and for a longer period during the 1960s and 1970s. The growth rate peaked at 2.2%
in 1963, and had declined to 1.1% by 2011. Total annual births were highest in the late 1980s
at about 138 million,
[7]
and are now expected to remain essentially constant at their 2011
level of 134 million, while deaths number 56 million per year, and are expected to increase to
80 million per year by 2040.
[8]

Current projections show a continued increase in population in the near future (but a steady
decline in the population growth rate), with the global population expected to reach between
7.5 and 10.5 billion by 2050.
[2][9][10]
Various longer-term estimates predict further growth,
stagnation, or even overall decline in the global population by 2150.
[11]
Some analysts have
questioned the sustainability of further world population growth, citing the growing pressures
on the environment, global food supplies, and energy resources.
[12][13][14]

World population (millions)
[15]

2

#
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 148 142 137
10 Japan 124 128 126

World total 5,265 6,688 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 148 142 137

+ ex-Soviet Union* 133 136 146
4 Latin America 355 462 550
5 North America* 359 444 514
6 Middle East 132 199 272

Australia 17 22 28

European Union 27 states 473 499 539

US + Canada 278 338 392

Ex-Soviet Union 289 285 289
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
ex-Soviet Union (SU) = SU 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
Contents
1 Population by region
o 1.1 Population by continent
2 Milestones by the billions
3 History
o 3.1 Antiquity and Middle Ages
o 3.2 Modern era
4 Global demographics
5 Largest populations by country
3

o 5.1 Most densely populated countries
6 Fluctuation
o 6.1 Forecasts
o 6.2 Population growth by region
7 Mathematical approximations
o 7.1 Years for world population to double
8 Overpopulation
o 8.1 Predictions of scarcity
o 8.2 Environmental impacts
o 8.3 Population control
9 Number of humans who have ever lived
o 9.1 Estimation methodologies
10 United Nations population agencies
11 See also
12 Notes
13 References
14 External links
Population by region
Six of Earth's seven continents are permanently inhabited on a large scale. Asia is the most
populous continent, with its 4.2 billion inhabitants accounting for over 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 11% of the world's population, 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%).
[16]
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.
[17]

Population by continent
Continent
Density
(inhabitants/km
2
)
Population
(2011)
Most populous
country
Most populous city
Asia 86.7 4,140,336,501
China
(1,341,403,687)
Tokyo
(35,676,000)
Africa 32.7 994,527,534
Nigeria
(152,217,341)
Cairo
(19,439,541)
Europe 70 738,523,843
Russia
(143,300,000;
approx. 110
million in Europe)
Moscow
(14,837,510)
4

North
America
22.9 528,720,588
United States
(313,485,438)
Mexico
City/Metro Area
(8,851,080 /
21,163,226)
South
America
21.4 385,742,554
Brazil
(190,732,694)
So Paulo
(19,672,582)
Oceania 4.25 36,102,071
Australia
(22,612,355)
Sydney
(4,575,532)
Antarctica 0.0003 (varies)
4,490 (non-
permanent,
varies)
[18]

N/A
[note 1]

McMurdo
Station (955)
[19]

Milestones by the billions
Main article: World population milestones
World population milestones (USCB estimates)
Population
(in billions)
1 2 3 4 5 6 7 8 9
Year 1804 1927 1960 1974 1987 1999 2012 2027 2046
Years
elapsed
between
milestones
123 33 14 13 12 13 15 19
It is estimated that the world population reached one billion for the first time in 1804. It was
another 123 years before it reached two billion in 1927, but it took only 33 years to reach
three billion in 1960. Thereafter, the global population reached four billion in 1974, five
billion in 1987, six billion in 1999 and, according to the United States Census Bureau, seven
billion in March 2012.
[1]
The United Nations, however, estimated that the world population
reached seven billion in October 2011.
[3][4][5]

According to current projections, the global population will reach eight billion by 2030, and
will likely reach around nine billion by 2050. Alternative scenarios for 2050 range from a low
of 7.4 billion to a high of more than 10.6 billion.
[20]
Projected figures vary depending on
underlying statistical assumptions and the variables used in projection calculations, especially
the fertility variable. Long-range predictions to 2150 range from a population decline to 3.2
billion in the 'low scenario', to 'high scenarios' of 24.8 billion. One extreme scenario predicted
a massive increase to 256 billion by 2150, assuming the global fertility rate remained at its
1995 level of 3.04 children per woman; however, by 2010 the global fertility rate had
declined to 2.52.
[11][21]

There is no estimation for the exact day or month the world's population surpassed one or two
billion. The days of three and four billion were not officially noted, but the International
Database of the United States Census Bureau places them in July 1959 and April 1974. 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.
[22]

5

History
See also: World population estimates and History of the world
Antiquity and Middle Ages
Main articles: Classical demography and Medieval demography
A dramatic population bottleneck is theorized for the period around 70,000 BC as a result of
the Toba supervolcano eruption. From this time until the development of agriculture around
the 11th millennium BC, it is estimated that the world population stabilized at about one
million people, whose subsistence entailed hunting and foraging a lifestyle that by its nature
ensured a low population density. The total world population probably never exceeded 15
million inhabitants before the invention of agriculture.
[23]
By contrast, it is estimated that
around 5060 million people lived in the combined eastern and western Roman Empire in the
4th century AD.
[24]

The plague which first emerged during the reign of Justinian caused Europe's population to
drop by around 50% between 541 and the 8th century.
[25]
The population of Europe was more
than 70 million in 1340.
[26]
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;
[27]
it took roughly 200 years for Europe's population to regain its 1340 level.
[28]

China experienced a population decline from an estimated 123 million around 1200 to an
estimated 65 million in 1393,
[29]
which was presumably due to a combination of Mongol
invasions and plague.
[30]

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.
[31]

England's population reached an estimated 5.6 million in 1650, up from an estimated 2.6
million in 1500.
[32]
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.
[33][34]
Since their introduction by Portuguese traders in the 16th century,
[35]
maize and
cassava have replaced traditional African crops as that continents most important staple food
crops.
[36]

The total population of the Americas in 1500 may have been between 50 and 100 million.
[37]

The pre-Columbian North American population probably numbered somewhere between 2
million and 18 million.
[38]
Encounters between European explorers and populations in the rest
of the world often introduced local epidemics of extraordinary virulence.
[39]
Archaeological
evidence indicates that the death of around 90% of the Native American population of the
New World was caused by Old World diseases such as smallpox, measles and influenza.
[40]

Over the centuries, the Europeans had developed high degrees of immunity to these diseases,
while the indigenous peoples had no such immunity.
[41]

Modern era
6


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.
[42]
By 2050, the proportion may reach 70%.
[43]

During the European Agricultural and Industrial Revolutions, the life expectancy of children
increased dramatically.
[44]
The percentage of the children born in London who died before the
age of five decreased from 74.5% in 17301749 to 31.8% in 18101829.
[45][46]
Between 1700
and 1900, Europes population increased from about 100 million to over 400 million.
[47]

Altogether, the areas of European settlement comprised 36% of the world's population in
1900.
[48]

Population growth in the West became more rapid after the introduction of compulsory
vaccination and improvements in medicine and sanitation.
[49]
As living conditions and health
care improved during the 19th century, the United Kingdom's population doubled every fifty
years.
[50]
By 1801, the population of England had grown to 8.3 million, and by 1901 it had
reached 30.5 million; the population of the United Kingdom reached 60 million in 2006.
[51]

The United States saw its population grow from around 5.3 million in 1800 to 106 million in
1920, exceeding 307 million in 2010.
[52]

The first half of the 20th century in Russia and the Soviet Union was marked by a succession
of wars, famines and other disasters, each accompanied by large-scale population losses.
[53]

By the end of World War II in 1945, the Russian population was about 90 million fewer than
it could have been otherwise.
[54]
In recent decades, Russia's population has declined
significantly from 148 million in 1991 to 143 million in 2012 and may sink as low as 107
million by 2050, if current demographic trends continue.
[55]

Many countries in the developing world have experienced rapid population growth over the
past century. China's population rose from approximately 430 million in 1850 to 580 million
in 1953,
[56]
and now stands at over 1.3 billion. The population of the Indian subcontinent,
which stood at about 125 million in 1750, reached 389 million in 1941;
[57]
today, India and its
surrounding countries are home to about 1.6 billion people.
[58]
The population of Java
increased from about five million in 1815 to more than 130 million in the early 21st
century.
[59]
Mexico's population grew from 13.6 million in 1900 to about 112 million in
2009.
[60]
Between the 1920s and 2000s, Kenya's population grew from 2.9 million to 37
million.
[61]

Global demographics
Main article: Demographics of the world
7


Chart showing geographic distribution of the world population in 2005.
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.
[62][63]
Approximately 26.3% of the global population is aged under 15, while
65.9% is aged 1564 and 7.9% is aged 65 or over.
[62]
At the beginning of 2012, 50.5% of the
world's population was under 30;
[64]
as of the end of 2012, the median age of the human race
is about 30 years. The global average life expectancy is 67.07 years,
[62]
with women living an
average of 69 years and men approximately 65 years.
[62]
In 2010, the global fertility rate was
estimated at 2.52 children per woman.
[21]
83% of the world's over-15s are considered
literate.
[62]
In June 2012, British researchers calculated the total weight of Earth's human
population as 287 million tonnes, with the average person weighing 62 kilograms (140 lb).
[65]

The nominal 2011 gross world product was estimated at US$69.11 trillion, giving an annual
global per capita figure of around US$9,900.
[66]
Around 1.29 billion people (18.4% of the
world population) live in extreme poverty, subsisting on less than US$1.25 per day;
[67]

approximately 925 million people (13.2%) are malnourished.
[68]
In December 2011, there
were around 2.26 billion global Internet users, constituting 32.7% of the world population.
[69]

The Han Chinese are the world's largest single ethnic group, constituting over 19% of the
global population, while the second-largest single ethnicity, the Bengali people, account for
around 4.8%.
[70]
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%).
[62]
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%.
[62]
In 2005, around 16% of the
global population were reported to be non-religious.
[71]

Largest populations by country
Further information: List of countries by population
8


A map of the world's countries by total population, with darker shading indicating larger
populations.
The 10 countries with the largest total population:
Rank Country / Territory Population Date
% of world
population
Source
1 China
[note 2]
1,357,180,000 April 20, 2013 19.2%
[72]

2 India 1,210,193,422 March 2011 17%
[73]

3 United States 315,706,000 April 20, 2013 4.46%
[74]

4 Indonesia 237,641,000 May 2010 3.36%
[75]

5 Brazil 198,028,000 April 20, 2013 2.8%
[76]

6 Pakistan 182,830,000 April 20, 2013 2.58%
[77]

7 Nigeria 170,123,740 July 2012 2.4%
[78]

8 Bangladesh 161,083,804 July 2012 2.28%
[79]

9 Russia 141,927,297 January 1, 2010 2.005%
[80]

10 Japan 127,547,000 June 1, 2012 1.8%
[81]

Approximately 4.06 billion people live in these ten countries, representing around 58% of the
world's population as of November 2012.
Most densely populated countries
Further information: List of countries and dependencies by population density
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 km
2
) map of the world in 1994. Red and pink areas denote
regions of highest population density.
10 most densely populated countries (with population above 1 million)
9

Rank Country/Region Population Area (km
2
)
Density
(Pop. per km
2
)
1 Singapore 5,183,700 710 7301
2 Bahrain 1,234,596 750 1646
3 Bangladesh 152,518,015 147,570 1034
4 Taiwan 23,293,593 36,190 644
5 Mauritius 1,288,000 2,040 631
6 South Korea 50,004,441 99,538 502
7 Lebanon 4,292,000 10,452 411
8 Rwanda 10,718,379 26,338 407
9 Netherlands 16,775,273 41,526 404
10 Belgium 11,139,292 30,528 365
Countries ranking highly in terms of both total population (more than 15 million people) and
population density (more than 250 people per square kilometer):
Country Population Area (km
2
)
Density
(Pop. per
km
2
)
Notes
India 1,227,640,000 3,287,240 373 Growing country
Bangladesh 152,518,015 147,570 1034 Growing country
Japan 127,547,000 377,873 338 Declining in population
Philippines 94,013,200 300,076 313 Fast-growing country
Vietnam 85,789,573 331,689 259 Growing country
United Kingdom 62,262,000 243,610 256 Growing country
[82]

South Korea 50,004,441 99,538 502 Steady in population
[83]

Taiwan 23,293,593 36,190 644
Declining in
population
[84][85]

Sri Lanka 20,277,597 65,610 309 Growing country
Netherlands 16,850,000 41,526 406 Steady in population
Fluctuation
Main article: Population growth
10


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. According to the United Nations, population growth on Earth's inhabited continents
between 2000 to 2005 totalled:
227,771,000 in Asia;
92,293,000 in Africa;
38,052,000 in Latin America;
16,241,000 in Northern America;
3,264,000 in Europe;
1,955,000 in Oceania;
383,047,000 overall.
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.
[86][87][88]

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),
[89]
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. According to data from the CIA's 20052006 World Factbooks, the
world population increased by an average of 203,800 people every day in the mid-2000s.
[90]

The World Factbook increased this estimate to 211,090 people every day in 2007, and again
to 220,980 people every day in 2009.
11


A world map showing global variations in fertility rate per woman, according to the CIA
World Factbook's 2013 data.
78 Children
67 Children
56 Children
45 Children
34 Children
23 Children
12 Children
01 Children
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.
[91]

In some countries, there is negative population growth (i.e. net decrease in population over
time), especially in Central and Eastern Europe this is mainly due to low fertility rates.
During the 2010s, Japan and some countries in Western Europe are also expected to
encounter negative population growth, due to sub-replacement fertility rates.
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.
[92]

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.
[93]


Estimated world population figures, 10,000 BC2000 AD.

Estimated world population figures, 10,000 BC2000 AD (in log y scale).

World population figures, 19502000.
12


Estimated global growth rates, 19502050.

Estimated and projected populations of the world and its continents (except
Antarctica) from 1950 to 2100. The shaded regions correspond to the range of
projections by the United Nations Department of Economic and Social Affairs.
Forecasts
Main article: World population estimates
UN (medium variant 2010 revision) and US Census Bureau (December 2010)
estimates
[94][95]

Year
UN est.
(millions)
Difference
USCB est.
(millions)
Difference
2000 6,123 6,090
2010 6,896 773 6,852 763
2020 7,657 761 7,593 740
2030 8,321 665 8,249 656
2040 8,874 553 8,801 552
2050 9,306 432 9,256 456
Long-term global population growth is difficult to predict. The United Nations and the US
Census Bureau both give different estimates according to the latter, the world population
13

reached seven billion in March 2012,
[96]
while the UN asserted that this occurred in late
2011.
[10]
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 slightly, 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 2008 estimates and medium variant projections (in millions)
[97]

Year World Asia Africa Europe
Latin
America
Northern
America
Oceania
2000 6,115
3,698
(60.5%)
819 (13.4%)
727
(11.9%)
521 (8.5%) 319 (5.2%)
31
(0.5%)
2005 6,512
3,937
(60.5%)
921 (14.1%)
729
(11.2%)
557 (8.6%) 335 (5.1%)
34
(0.5%)
2010 6,909
4,167
(60.3%)
1,033
(15.0%)
733
(10.6%)
589 (8.5%) 352 (5.1%)
36
(0.5%)
2015 7,302
4,391
(60.1%)
1,153
(15.8%)
734
(10.1%)
618 (8.5%) 368 (5.0%)
38
(0.5%)
2020 7,675
4,596
(59.9%)
1,276
(16.6%)
733 (9.6%) 646 (8.4%) 383 (5.0%)
40
(0.5%)
2025 8,012
4,773
(59.6%)
1,400
(17.5%)
729 (9.1%) 670 (8.4%) 398 (5.0%)
43
(0.5%)
2030 8,309
4,917
(59.2%)
1,524
(18.3%)
723 (8.7%) 690 (8.3%) 410 (4.9%)
45
(0.5%)
2035 8,571
5,032
(58.7%)
1,647
(19.2%)
716 (8.4%) 706 (8.2%) 421 (4.9%)
46
(0.5%)
2040 8,801
5,125
(58.2%)
1,770
(20.1%)
708 (8.0%) 718 (8.2%) 431 (4.9%)
48
(0.5%)
2045 8,996
5,193
(57.7%)
1,887
(21.0%)
700 (7.8%) 726 (8.1%) 440 (4.9%)
50
(0.6%)
2050 9,150
5,231
(57.2%)
1,998
(21.8%)
691 (7.6%) 729 (8.0%) 448 (4.9%)
51
(0.6%)
Population growth by region
The table below shows historical and predicted regional population figures in
millions.
[97][98][99][100]
The availability of historical population figures varies by region.
World historical and predicted populations (in millions)
[101][102]

Region 1500 1600 1700 1750 1800 1850 1900 1950 1999 2008 2050 2150
World 458 580 682 791 978 1,262 1,650 2,521 5,978 6,707 8,909 9,746
Africa 86 114 106 106 107 111 133 221 767 973 1,766 2,308
14

World historical and predicted populations (in millions)
[101][102]

Region 1500 1600 1700 1750 1800 1850 1900 1950 1999 2008 2050 2150
Asia 243 339 436 502 635 809 947 1,402 3,634 4,054 5,268 5,561
Europe 84 111 125 163 203 276 408 547 729 732 628 517
Latin America and the
Caribbean
[Note 1]

39 10 10 16 24 38 74 167 511 577 809 912
Northern America
[Note 1]
3 3 2 2 7 26 82 172 307 337 392 398
Oceania 3 3 3 2 2 2 6 13 30 34 46 51
World historical and predicted populations by percentage distribution
[101][102]

Region 1500 1600 1700 1750 1800 1850 1900 1950 1999 2008 2050 2150
World 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 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 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 7.0 5.3
Latin America and the
Caribbean
[Note 1]

8.5 1.7 1.5 2.0 2.5 3.0 4.5 6.6 8.5 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 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
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
Oceania Notes
70,000
BC
< 0.015

[103]

10,000
BC
1

9000
BC
3

8000
BC
5

[104]

7000
BC
7

6000
BC
10

5000
BC
15

4000
BC
20

3000
BC
25

2000 35

15

BC
1000
BC
50

[104]

500
BC
100

[104]

AD 1 200

[105]

1000 310

1750 791 106 502 163 16 2 2

1800 978 107 635 203 24 7 2

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

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
[106]

1. ^
a

b

c

d

e
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, S. von Hoerner proposed a formula for population growth which represented
hyperbolic growth with an infinite population in 2025.
[108]
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.
[109]

According to Sergei Kapitsa,
[110]
the world population grew between 67,000 BC and 1965
according to the following formula:
16


where
N is current population
T is the current year
C = (1.860.01)10
11

T
0
= 20071
= 421
The transition from hyperbolic growth to slower rates of growth is related to the demographic
transition.
Years for world population to double
Using linear interpolation and extrapolation of UNDESA population estimates, the world
population has doubled, or will double, in the following years (with two different starting
points). Note how, during the 2nd millennium, 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.
[111]



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

17

Overpopulation
Main article: Overpopulation
Predictions of scarcity
In 1798, the British scholar Thomas Malthus incorrectly predicted that continued population
growth would exhaust the global food supply by the mid-19th century. In 1968, Paul R.
Ehrlich reprised this argument in The Population Bomb, predicting that mass global famine
would occur in the 1970s and 1980s. The predictions of Ehrlich and other neo-Malthusians
were vigorously challenged by a number of economists, notably Julian Lincoln Simon.
Agricultural research already under way, such as the Green Revolution, led to dramatic
improvements in crop yields. Food production has so far kept pace with population growth,
but neo-Malthusians point out that the Green Revolution relies heavily on petroleum-based
fertilizers, and that many crops have become so genetically uniform that a crop failure could
potentially have global repercussions.


Graph of the global human population from 10,000 BC to 2010 AD, from the US Census
Bureau. The graph shows the extremely rapid growth in the world population that has taken
place since the 18th century.
From 1950 to 1984, as the Green Revolution transformed agriculture around the world, grain
production increased by over 250%.
[112]
The world population has grown by about four
billion since the beginning of the Green Revolution, and most scholars believe that, without
the Revolution, there would be greater levels of famine and malnutrition than the UN
presently documents.
[113]
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.
The potential peaking of world oil production may test the critics of Malthus and Ehrlich, as
oil is of crucial importance to global transportation, power generation and agriculture.
[114]
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/m
3
),
[115]
global population
growth,
[116]
the effects of climate change,
[117]
the loss of agricultural land to residential and
industrial development,
[118][119]
and growing consumer demand in the population centres of
China and India.
[120][121]
Food riots subsequently occurred in some countries.
[122][123]

However, oil prices then fell sharply, and remained below $100/barrel until around 2010.
18

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.
[124][125]

Richard C. Duncan claims the that the world population will decline to about 2 billion around
2050.
[126]
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 2013 is over 310 million.
[127]
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" by
2030. Beddington claimed that food reserves were at a fifty-year low, and that the world
would require 50% more energy, food and water by 2030.
[128][129]
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.
[130]

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.
[131]
The 2009 FAO estimates showed an even more dramatic increase, to
1.02 billion.
[132]

Environmental impacts
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.
[133][134]
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.
[135]
Indeed, some analysts claim that
overpopulation's most serious impact is its effect on the environment.
[13]
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
Main article: Human population control
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,
religious reasons, and overpopulation. The use of abortion in some population control
strategies has caused controversy,
[136]
with organizations such as the Roman Catholic Church
explicitly opposing any intervention in the human reproductive process.
[137]

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
19

aggregate ecological endowment of our planet."
[138]
The book Fatal Misconception by
Matthew Connelly similarly points to the importance of supporting the rights of women in
bringing population levels down over time.
Number of humans who have ever lived
Further information: Paleodemography
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 totalled approximately 107 billion.
[139][140]
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".
[140]
Given an
estimated global population of 7 billion in 2011, it could be inferred that about 6.5% of all
people who had ever existed were alive in 2011.
[139]
Various estimates published in the first
decade of the 21st century give figures ranging from approximately 100 billion to 115 billion.
In the 1970s, claims emerged alleging that 75% of all the people who had ever lived were
alive at that time. This view was eventually debunked as unscientific.
[141]

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 limited size of the world population in prehistoric times (as compared to its current
size) makes this source of 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 people for purposes of taxation or military service.
[142]
All claims of
population sizes preceding the 18th century are imprecise 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.
Another critical factor for such an estimate is life expectancy. Using an average figure of
twenty years and the population estimates above, one can compute a total of about 58 billion.
Using a figure of forty yields around 30 billion. However, life expectancy varies greatly when
taking into account children who died before their first birthday, a number very difficult to
estimate for earlier times. Haub states that "life expectancy at birth probably averaged only
about ten years for most of human history".
[140]
His estimates for infant mortality suggest that
around 40% of those who have ever lived did not survive beyond their first birthday.
United Nations population agencies
20

The United Nations operates several organisations with various population-related
competencies, including the Commission on Population and Development, the United
Nations Population Division, and the United Nations Population Fund.
See also
Birth control
Demographic transition
Depopulation
Doomsday argument
Family planning
Food security
Megacity
Coastal population
Natalism
One-child policy
Two-child policy
World's largest cities
Historical:
Historical demography
National Commission for the Observance of World Population Year 1974
Lists:
List of religious populations
List of countries by past and future population
List of countries by population in 1900
List of countries by population density
List of countries by population growth rate
List of countries by fertility rate
Lists of organisms by population for non-human global populations
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
"U.S. Census Bureau World POPClock Projection". July 2012July 2013 data.
The number on this page is automatically updated daily.
2. ^
a

b
"World Population Clock Worldometers". Worldometers.info. Retrieved April
12, 2012.
3. ^
a

b
"Population seven billion: UN sets out challenges". BBC. October 26, 2011.
Retrieved October 27, 2011.
4. ^
a

b
"World's 'seven billionth baby' is born". The Guardian. October 31, 2011.
Retrieved 2011-10-31.
5. ^
a

b
"7 billion people is a 'serious challenge'". UPI. October 31, 2011. Retrieved
2011-11-09.
21

6. ^ Jean-Nol Biraben, 1980, "An Essay Concerning Mankind's Evolution", Population,
Selected Papers, Vol. 4, pp. 113. Original paper in French: (b) Jean-Nol Biraben,
1979, "Essai sur l'volution du nombre des hommes", Population, Vol. 34 (no. 1), pp.
1325.
7. ^ World Population Prospects, 2010 revision (686 million births from 19851990).
United Nations. Retrieved February 14, 2013.
8. ^ "World Population estimates by the US Census Bureau". USCB. Retrieved May 22,
2012.
9. ^ "International Data Base (IDB) World Population". Census.gov. June 28, 2010.
Retrieved August 1, 2010.
10. ^
a

b
"World Population Prospects:The 2008 Revision". Population Division of the
Department of Economic and Social Affairs of the United Nations Secretariat. June
2009. Retrieved 12 February 2013.
11. ^
a

b
Key Findings. "Long-Range Population Projections". Proceedings of the United
Nations Technical Working Group on Long-Range Population Projections (New
York: United Nations: Department of Economic and Social Affairs). 2003. Retrieved
July 3, 2010.
12. ^ An Introduction To Sustainable Development Page 53, Peter P. Rogers, Kazi F.
Jalal, John A. Boyd (2008).
13. ^
a

b
"Overpopulation's Real Victim Will Be the Environment". TIME. 26 October
2011. Retrieved 18 February 2013.
14. ^ Zehner, Ozzie (2012). Green Illusions. Lincoln and London: University of
Nebraska Press. pp. 187331.
15. ^ CO2 Emissions from Fuel Combustion Population 19712008 (pdf, pp. 8385) IEA
(OECD/ World Bank) (original population ref OECD/ World Bank, e.g., in IEA Key
World Energy Statistics 2010-page 57)
16. ^ "World Population Prospects: The 2010 Revision Population Database". United
Nations. April 15, 2011. Retrieved 2012-04-21.
17. ^ "Life on an Antarctic Station". Antarctic Connection. Retrieved 2011-10-28.
18. ^ CIA World Factbook, March 2011 data. Retrieved 2011-12-24.
19. ^ "What is the population of McMurdo this time of year?". Antarctic Adventures,
2011-05-01. Retrieved 2011-10-28.
20. ^
"Ch. 5: Population Size and Composition". World Population Prospects, the
2000 Revision. Vol.III. United
Nations Population Division. p. 171. Retrieved 2010-07-03.
"Executive Summary". World Population Prospects: The 2002 Revision
Volume III: Analytical Report. 2002. Retrieved 2010-07-03.
World Population to 2300. New York: United Nations Department of
Economic and Social Affairs: Population Division. pp. 3, 14. 2004. Retrieved
2010-07-03.
World Population: 19502050. U.S. Census Bureau, Population Division.
Update as at June 2010. Retrieved 2010-07-03.
2009 World Population Data Sheet. Washington, DC: Population Reference
Bureau. 2009. Retrieved 2010-07-03.
21. ^
a

b
"Total fertility estimates, 19502010". UN Population Division. April 2011.
Retrieved 2012-06-14.
22

22. ^ "World Population Prospects, the 2008 Revision Frequently Asked Questions".
Population Division of the Department of Economic and Social Affairs of the United
Nations Secretariat. Updated November 10, 2010. Retrieved 2011-01-26.
23. ^ Luc-Normand Tellier (2009). "Urban world history: an economic and geographical
perspective". PUQ. p.26. ISBN 2-7605-1588-5
24. ^ "Population estimates of the Roman Empire". Dr. Kenneth W. Harl. Tulane.edu.
1998. Retrieved 8 December 2012.
25. ^ "Plague, Plague Information, Black Death Facts, News, Photos". National
Geographic. Retrieved 2008-11-03.
26. ^ "History of Europe Demographic and agricultural growth". Encyclopdia
Britannica. 2012. Retrieved 17 December 2012.
27. ^ "Historical Estimates of World Population". Census.gov. Retrieved 2008-11-03.
28. ^ "A Distant Mirror". TIME Europe. July 17, 2000. Vol. 156 No. 3.
29. ^ Horst R. Thieme (2003). "Mathematics in population biology". Princeton University
Press. p.285. ISBN 0-691-09291-5.
30. ^ Graziella Caselli, Gillaume Wunsch, Jacques Vallin (2005). "Demography:
Analysis and Synthesis, Four Volume Set: A Treatise in Population". Academic Press.
p.34. ISBN 0-12-765660-X.
31. ^ "Qing China's Internal Crisis: Land Shortage, Famine, Rural Poverty". Asia for
Educators. Columbia University.
32. ^ "History of Europe Demographics". Encyclopdia Britannica.
33. ^ "China's Population: Readings and Maps". Columbia University: East Asian
Curriculum Project. Retrieved 18 December 2012.
34. ^ "The Columbian Exchange". University of North Carolina. Retrieved 18 December
2012.
35. ^ Super-Sized Cassava Plants May Help Fight Hunger In Africa. The Ohio State
University
36. ^ "Albert Schweitzer: a biography". James Brabazon (2000). Syracuse University
Press. p.242. ISBN 0-8156-0675-3.
37. ^ J. N. Hays (1998). The burdens of disease: epidemics and human response in
western history. p 72. ISBN 0-8135-2528-4.
38. ^ "Microchronology and Demographic Evidence Relating to the Size of Pre-
Columbian North American Indian Populations". Science.
39. ^ Arthur C. Aufderheide, Conrado Rodrguez-Martn, Odin Langsjoen (1998). The
Cambridge encyclopedia of human paleopathology. Cambridge University Press.
p.205. ISBN 0-521-55203-6.
40. ^ "The Story Of... Smallpox and other Deadly Eurasian Germs". Public
Broadcasting Service (PBS).
41. ^ 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.
42. ^ World Demographics Profile 2012. Index Mundi. Retrieved 2012-05-22.
43. ^ "By 2050, 70% of the world's population will be urban. Is that a good thing?" Fast
Co. Design. 2012. Retrieved 2012-05-01.
44. ^ Population crises and cycles in history. A review of the book Population Crises and
Population cycles by Claire Russell and W.M.S. Russell.
45. ^ 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.
46. ^ BBC History The Foundling Hospital. Published 2001-05-01.
23

47. ^ "Modernization Population Change". Encyclopdia Britannica. Retrieved 6
February 2013.
48. ^ Graziella Caselli, Gillaume Wunsch, Jacques Vallin (2005). "Demography:
Analysis and Synthesis, Four Volume Set: A Treatise in Population". Academic Press.
p.42. ISBN 0-12-765660-X.
49. ^ History Victorian Medicine From Fluke to Theory. BBC. 1 February 2002.
Retrieved 2013-02-17.
50. ^ "A portrait of Britain in 2031". The Independent. 24 October 2007. Retrieved 2013-
02-17.
51. ^ "UK population breaks through 60m". BBC. 24 August 2006. Retrieved 2012-04-
14.
52. ^ "US population through history". About.com. Retrieved 2012-04-14.
53. ^ Mark Harrison (2002). "Accounting for War: Soviet Production, Employment, and
the Defence Burden, 19401945". Cambridge University Press. p.167. ISBN 0-521-
89424-7
54. ^ Stephen J. Lee (2000). "European dictatorships, 19181945". Routledge. p.86.
ISBN 0-415-23046-2
55. ^ "Vladimir Putin vows to reverse Russian population decline". The Daily Telegraph.
13 February 2012. Retrieved 2012-04-13.
56. ^ "China's demographic evolution 18501953 reconsidered" (1978). The China
Quarterly via JSTOR. Retrieved 2012-04-13.
57. ^ "Reintegrating India with the World Economy" (PDF). Peterson Institute for
International Economics. 2003. Retrieved 8 November 2012.
58. ^ CIA World Factbook. July 2012 estimate. Retrieved 2012-10-21.
59. ^ Java (island, Indonesia). Encyclopdia Britannica.
60. ^ Jorge Durand. "From Traitors to Heroes: 100 Years of Mexican Migration
Policies". University of Guadalajara. March 2004.
61. ^ Gunnar Heinsohn. "Kenya's Violence: Exploding population". The New York Times.
7 January 2008.
62. ^
a

b

c

d

e

f

g
"World Demographics Profile 2011". Index Mundi. Retrieved 18
November 2011.
63. ^ "Sex-ratio imbalance in Asia: Trends, consequences and policy responses".
UNFPA. 2007. Retrieved 2012-05-20.
64. ^ "Special Report: The Worlds Youngest Populations". Euromonitor International.
13 February 2012. Retrieved 29 November 2012.
65. ^ "Global weight gain more damaging than rising numbers". BBC. 18 June 2012.
Retrieved 12 February 2013.
66. ^ "World". CIA World Factbook. 13 November 2012. Retrieved 16 November 2012.
67. ^ "What It Will Take to 'Graduate' 1.2 Billion People Out of Extreme Poverty".
Huffington Post. 4 April 2012. Retrieved 26 April 2012.
68. ^ 2012 World Hunger and Poverty Facts and Statistics. WorldHunger.org. 2012.
Retrieved 26 April 2012.
69. ^ Internet World Stats. December 2011 data. Retrieved 22 April 2012
70. ^ "Worlds Most Typical Person: Han Chinese Man". Wall Street Journal. 4 March
2011. Retrieved 18 November 2011.
71. ^ Religions by adherents. Adherents.com. 2005 data. Retrieved 19 December 2011.
72. ^ Chinese Official Population Clock (in Chinese). CPDRC.org.cn. Updated daily.
Retrieved 2012-05-22.
73. ^ 2011 Census. Census of India. 2011. Retrieved 2012-05-22.
24

74. ^ United States Official Population Clock. USCB. Updated daily. Retrieved 2012-05-
22.
75. ^ "2010 Population Census (PowerPoint)". OchaOnline.un.org. 28 February 2012.
Retrieved 13 November 2012.
76. ^ Brazilian Official Population Clock. IBGE.gov.br. Retrieved 2012-05-22.
77. ^ Official Pakistani Population Clock. Population Census Organization of Pakistan.
Retrieved 15 November 2012.
78. ^ Nigeria. CIA World Factbook estimate. 10 May 2012. Retrieved 2012-05-22.
79. ^ Bangladesh. CIA World Factbook estimate. 7 May 2012. Retrieved 2012-05-22.
80. ^ Federal State Statistics Service of Russia (Excel document, in Russian). GKS.ru.
2010. Retrieved 2012-05-22.
81. ^ Official Japan Statistics Bureau. October 2012 provisional estimate.
82. ^ UK population 'to increase to 70 million by 2027'. BBC. October 26, 2011.
Retrieved 2012-04-10.
83. ^ "Demographic shifts accelerate". The Korea Times. August 26, 2012. Retrieved
2012-08-28.
84. ^ "Why Has Taiwan's Birthrate Dropped So Low?" TIME, December 7, 2009.
Retrieved 2011-12-17.
85. ^ "Taiwan Birth Rate Falls to Worlds Lowest". VoA. August 17, 2011. Retrieved
2011-12-17.
86. ^ "The limits of a Green Revolution?". BBC News. March 29, 2007. Retrieved 2010-
08-01.
87. ^ "The Real Green Revolution". Energybulletin.net. Archived from the original on
2008-06-23. Retrieved 2010-08-01.
88. ^ World Population to 2300 Economic and Social Affairs, United Nations, 2004
89. ^ "International Programs". USCB. January 7, 2009. Retrieved December 16, 2012.
90. ^ "Current world population (ranked)". Xist.org. July 1, 2009. Retrieved 2010-08-01.
91. ^ Ron Nielsen, The little green handbook, Picador, New York (2006) ISBN 0-312-
42581-3
92. ^ "UN 2006 report highlights" (PDF). Retrieved 2010-08-01.
93. ^ "UN population estimates and projections, database query, August 2009". United
Nations. March 11, 2009. Retrieved 2010-08-01.
94. ^ "World Population Prospects The 2010 Revision Population Database". United
Nations. 3 May 2011. Retrieved 6 May 2011.
95. ^ "US Census Bureau Total Midyear Population for the World: 19502050".
Census.gov. 1 December 2010. Retrieved 6 May 2011.
96. ^ "Notes on the World POPClock and World Vital Events". US Census Bureau.
Retrieved 12 February 2013.
97. ^
a

b
World Population Prospects: The 2008 Revision. United Nations. Retrieved 12
February 2013.
98. ^ "The World at". United Nations. 12 October 1999. Retrieved 1 August 2010.
99. ^ "Population Growth over Human History". University of Michigan. 4 January 2006.
Retrieved 9 March 2013.
100. ^ "Geo Hive: the population of continents, regions and countries". Xist.org. 1
July 2008. Retrieved 1 August 2010.
101. ^
a

b
Figures include the former Soviet countries in Europe. Caselli, Graziella;
Gillaume Wunsch, Jacques Vallin (20 December 2005). Demography: Analysis and
Synthesis, Four Volume Set: A Treatise in Population. Academic Press. p. 42.
ISBN 978-0-12-765660-1.
102. ^
a

b
"UN report 2004 data" (PDF). Retrieved 1 August 2010.
25

103. ^ Fewer than 15,000 individuals, according to the Toba catastrophe theory;
see also Humans lived in tiny, separate bands for 100,000 years. Breitbart.com.
Retrieved 12 February 2013.
104. ^
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" in
The Quarterly Journal of Economics 108(3): 681716.
105. ^ The range of figures from different sources as listed at the US Census
Bureau's Historical Estimates of World Population put the world population in AD 1
between 170 million and 400 million.
106. ^ "The population of continents, regions and countries". GeoHive. July 2010
data. Retrieved 12 February 2013.
107. ^ von Hoerner, S (1975). Journal of British Interplanetary Society 28691.
108. ^ 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".
109. ^ Sergei P Kapitza. "The phenomenological theory of world population
growth." Physics-Uspekhi 39(1) 5771 (1996).
110. ^ Letters to Nature: Doubling of world population unlikely. Nature. June 19,
1997. Retrieved October 23, 2012.
111. ^ Kindall, Henery W & Pimentel, David (May 1994). "Constraints on the
Expansion of the Global Food Supply". Ambio. 23 (3).
112. ^ "The limits of a Green Revolution?". BBC News. 29 March 2007. Retrieved
18 February 2013.
113. ^ "Peak Oil And Famine: Four Billion Deaths". Countercurrents.org. 29
October 2007. Retrieved 18 February 2013.
114. ^ "The global grain bubble". Christian Science Monitor. 18 January 2008.
Retrieved 18 February 2013.
115. ^ James Randerson, science correspondent (7 March 2008). "Food crisis will
take hold before climate change, warns chief scientist". The Guardian (London).
Retrieved 18 February 2013.
116. ^ John Vidal, environment editor (3 November 2007). "Global food crisis
looms as climate change and fuel shortages bite". The Guardian (London). Retrieved
18 February 2013.
117. ^ Walsoft (22 February 2008). "Experts: Global Food Shortages Could
Continue for Decades'". Marketoracle.co.uk. Retrieved 18 February 2013.
118. ^ "Has Urbanization Caused a Loss to Agricultural Land?". Moyak.com.
Retrieved 2010-08-01.
119. ^ Walt, Vivienne (27 February 2008). "The World's Growing Food-Price
Crisis". Time. Retrieved 18 February 2013.
120. ^ "The cost of food: Facts and figures". BBC. 16 October 2008. Retrieved 18
February 2013.
121. ^ Julian Borger (26 February 2008). "Feed the world? We are fighting a losing
battle, UN admits". The Guardian (London). Retrieved 18 February 2013.
122. ^ "Assessing the global food crisis". BBC. 22 April 2008. Retrieved 6 April
2010.
123. ^ "Half of all food 'wasted' report claims". BBC. 10 January 2013. Retrieved
10 January 2013.
124. ^ "Oil shock could push world food prices higher". CNN Money. 3 March
2011. Retrieved 18 February 2013.
26

125. ^ Steven Stoft (2008). Carbonomics: how to fix the climate and charge it to
OPEC. p.24. ISBN 0-9818775-0-8.
126. ^ P. Crabb (2000). North Atlantic Treaty Organization. Scientific Affairs
Division (2000). Implementing ecological integrity: restoring regional and global
environmental and human health. Springer. p.411. ISBN 0-7923-6351-5.
127. ^ "World faces 'perfect storm' of problems by 2030, chief scientist to warn".
The Guardian. 18 March 2009. Retrieved 18 February 2013.
128. ^ "Global crisis 'to strike by 2030'". BBC. 19 March 2009. Retrieved 18
February 2013.
129. ^ "Global food production will have to increase 70% for additional 2.3 billion
people by 2050". Finfacts.com. 24 September 2009. Retrieved 18 February 2013.
130. ^ Food and Agriculture Organization Economic and Social Development
Department. The State of Food Insecurity in the World, 2008: High food prices and
food security threats and opportunities. Food and Agriculture Organization of the
United Nations. 2008. p. 2. Retrieved 8 December 2012.
131. ^ One sixth of humanity undernourished more than ever before. Food and
Agriculture Organization of the United Nations. 2009. Retrieved 8 December 2012.
132. ^ "Ecological Debt Day". Retrieved 18 February 2013.
133. ^ "Planetary Boundaries: Specials". Nature. 23 September 2009. Retrieved 18
February 2013.
134. ^ IAP (login required). Retrieved 18 February 2013.
135. ^ Some population control programs, such as China's one-child policy, even
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 2012-08-29.
136. ^ "Fighting poverty to build peace". Vatican. January 1, 2009. Retrieved
2011-10-24.
137. ^ Zehmer, Ozzie (2012). Green lllusions. Lincoln and London: University of
Nebraska. p. 188.
138. ^
a

b
Curtin, Ciara (March 1, 2007). "Fact or Fiction?: Living People
Outnumber the Dead". Scientific American (Scientific American, Inc., published
September 2007) 297 (3): 126. doi:10.1038/scientificamerican0907-126. Retrieved
2008-08-04. Note: text of paper publication slightly different from text of on-line
publication
139. ^
a

b

c
Haub, Carl (November/December 2002). "How Many People Have Ever
Lived on Earth?". Population Today 30 (8) (Population Reference Bureau). pp. 34.
Retrieved 2008-08-04.
140. ^ "Population Reference Bureau". Prb.org. December 1, 2002. Retrieved
2010-08-01.
141. ^ Kuhrt, A. (1995). The Ancient Near East, c. 3000330 BC. Vol. 2.
Routledge, London. p. 695.