World Population

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Population density (people per km²) by country, 2006

Population by region as a percentage of world population (1750–2005) The term world population commonly refers to the total number of living humans on Earth at a given time. As of 9 July 2009 (UTC), the Earth's population is estimated by the United States Census Bureau to be 6.77 billion.[1] The world population has been growing continuously since the end of the Black Death around 1400.[2] There were also short term falls at other times due to plague, for example in the mid 17th century.[citation needed] The fastest rates of world population growth (above 1.8%) were seen briefly during the 1950s then for a longer period during the 1960s and 1970s (see graph). According to population projections, world population will continue to grow until around 2050. The 2008 rate of growth has almost halved since its peak of 2.2% per year, which was reached in 1963. World births have levelled off at about 134-million-per-year, since their peak at 163million in the late 1990s, and are expected to remain constant. However, deaths are only around 57 million per year, and are expected to increase to 90 million by the year 2050. Since births outnumber deaths, the world's population is expected to reach about 9 billion by the year 2040.[3][4]

Contents [hide]

• • • • • • • • • •

1 Population figures 2 Rate of increase o 2.1 Models o 2.2 Milestones o 2.3 Years for Population to Double 3 Distribution 4 The world's most populous nations 5 Ethnicity 6 Demographics of youth 7 Forecast 8 Predictions based on population growth 9 Number of humans who have ever lived 10 See also 11 Further resources 12 References

•

13 External links

• •

[edit] Population figures A dramatic population bottleneck is theorized for the period around 70,000 BCE (see Toba catastrophe theory). After this time and until the development of agriculture, 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. It is estimated that over 55 million people lived in the combined eastern and western Roman Empire (300–400 AD).[5] The Plague of Justinian caused Europe's population to drop by around 50% between 541 and the 700s.[6] The Black Death pandemic in the 14th century may have reduced the world's population from an estimated 450 million to between 350 and 375 million in 1400.[7] At the founding of the Ming dynasty in 1368, China's population was reported to be close to 60 million, and toward the end of the dynasty in 1644 it might have approached 150 million.[8] New crops that had come to Asia from the Americas via the Spanish colonizers in the 16th century contributed to the population growth.[9] Encounters between European explorers and populations in the rest of the world often introduced local epidemics of extraordinary virulence. Archaeological evidence indicates that the death of 90 to 95% of the Native American population of the New World was caused by Old World diseases such as smallpox, measles, and influenza.[10] Over the centuries, the Europeans had developed high degrees of immunity to these diseases, while the indigenous peoples had no such immunity.[11] During the Agricultural and Industrial Revolutions, the life expectancy of children increased dramatically.[12] 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.[13] Europe’s

population doubled during the 18th century, from roughly 100 million to almost 200 million, and doubled again during the 19th century.[14] The population of the Indian subcontinent, which stood at about 125 million in 1750, had reached 389 million by 1941.[15] Below is a table with historical and predicted population figures shown in millions.[16][17][18][19] The availability of historical population figures varies by region. World historical and predicted populations (in millions)[20] 1750 1800 1850 1900 1950 1999 2008 2050 2150 791 978 1,262 1,650 2,521 5,978 6,707 8,909 9,746 106 107 111 133 221 767 973 1,766 2,308 502 635 809 947 1,402 3,634 4,054 5,268 5,561 163 203 276 408 547 729 732 628 517

Region World Africa Asia Europe Latin America and 16 24 38 74 167 511 577 809 912 the Caribbean * Northern 2 7 26 82 172 307 337 392 398 America * Oceania 2 2 2 6 13 30 34 46 51 World historical and predicted populations by percentage distribution Region 1750 1800 1850 1900 1950 1999 2008 2050 2150 World 100 100 100 100 100 100 100 100 100 Africa 13.4 10.9 8.8 8.1 8.8 12.8 14.5 19.8 23.7 Asia 63.5 64.9 64.1 57.4 55.6 60.8 60.4 59.1 57.1 Europe 20.6 20.8 21.9 24.7 21.7 12.2 10.9 7.0 5.3 Latin America and 2.0 2.5 3.0 4.5 6.6 8.5 8.6 9.1 9.4 the Caribbean * Northern 0.3 0.7 2.1 5.0 6.8 5.1 5.0 4.4 4.1 America * Oceania 0.3 0.2 0.2 0.4 0.5 0.5 0.5 0.5 0.5 Estimated world population at various dates (in thousands) Latin Northern Year World Africa Asia Europe Oceania Notes America * America* 70,000 [21] < 1,000 BCE 10,000 1,000 BCE 9000 3,000 BCE [22] 8000 5,000

BCE 7000 BCE 6000 BCE 5000 BCE 4000 BCE 3000 BCE 2000 BCE 1000 BCE 500 BCE 1 1000 1750 1800 1850 1900 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 Jul. 1, 2008 Year

7,000 10,000 15,000 20,000 25,000 35,000 50,000

[22]

100,000

[22]

200,000 310,000 791,000 978,000 1,262,000 1,650,000 2,518,629 2,755,823 2,981,659 3,334,874 3,692,492 4,068,109 4,434,682 4,830,979 5,263,593 5,674,380 6,070,581 6,453,628

[23]

106,000 107,000 111,000 133,000 221,214 246,746 277,398 313,744 357,283 408,160 469,618 541,814 622,443 707,462 795,671 887,964

502,000 635,000 809,000 947,000 1,398,488 1,541,947 1,674,336 1,899,424 2,143,118 2,397,512 2,632,335 2,887,552 3,167,807 3,430,052 3,679,737 3,917,508

163,000 203,000 276,000 408,000 547,403 575,184 601,401 634,026 655,855 675,542 692,431 706,009 721,582 727,405 727,986 724,722

16,000 24,000 38,000 74,000 167,097 190,797 209,303 250,452 284,856 321,906 361,401 401,469 441,525 481,099 520,229 558,281

2,000 7,000 26,000 82,000 171,616 186,884 204,152 219,570 231,937 243,425 256,068 269,456 283,549 299,438 315,915 332,156

2,000 2,000 2,000 6,000 12,812 14,265 15,888 17,657 19,443 21,564 22,828 24,678 26,687 28,924 31,043 32,998

6,706,993

972,752 4,053,868

731,683

577,147

337,168

34,375

World

Africa

Asia

Europe

[1]

Latin Northern Oceania Notes America* America*

* Northern America comprises the northern countries and territories of North America: Canada, the United States, Greenland, Bermuda, and St. Pierre and Miquelon. Latin America comprises Middle America (Mexico, the nations of Central America, and the Caribbean) and South America.

[edit] Rate of increase Main article: Population growth

Population evolution in different continents. The vertical axis is logarithmic and is millions of people. Different regions have different rates of population growth. According to the above table, the growth in population of the different regions from 2000 to 2005 was: 237.771 million in Asia 92.293 million in Africa 38.052 million in Latin America 16.241 million in Northern America 1.955 million in Oceania -3.264 million in Europe 383.047 million in the whole world In the 20th century, the world saw the biggest increase in its population in human history due to lessening of the mortality rate in many countries due to medical advances and massive increase in agricultural productivity attributed to the Green Revolution.[24][25][26] In 2000, the United Nations estimated that the world's population was growing at the rate of 1.14% (or about 75 million people) per year,[27] down from a peak of 88 million per year in 1989. In the last few centuries, the number of people living on Earth has increased many times over. By the year 2000, there were 10 times as many people on Earth as there were 300 years ago. According to data from the CIA's 2005–2006 World Factbooks, the world human population increased by 203,800 every day.[28] The CIA Factbook increased this to 211,090 people every day in 2007, and again to 220,980 people every day in 2009.

Map of countries and territories by fertility rate 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.[29] In some countries there is negative population growth (i.e. net decrease in population over time), especially in Central and Eastern Europe (mainly due to low fertility rates) and Southern Africa (due to the high number of HIV-related deaths). Within the next decade, Japan and some countries in Western Europe are also expected to encounter negative population growth due to sub-replacement fertility rates. The United Nations states that population growth is rapidly declining due to the demographic transition. The world population is expected to peak at 9.2 billion in 2050.[2]

Population (est.) Population (est.) 10,000 World population 10,000 BC–2000 AD. BC–2000 AD in log y 1950–2000 scale

Increase rate 1950– 2000

[edit] Models Hoerner (1975) proposed the following formula:[30]

where • • • •

N is current population T is the current year C = 2·1011 T0 = 2025

but this represents hyperbolic growth with an infinite population in 2025.

According to Kapitza (1997)[31], the population grew between 67000 b.c. and 1965, and the word population growth formula is:

where • • • • •

N is current population T is the current year C = (1.86±0.01)·1011 T0 = 2007±1 τ = 42±1

The transition from hyperbolic growth to slower rates of growth is called demographic transition.

[edit] Milestones

World Population Milestones (Billions - estimated). World population estimates milestones . Population 1 2 3 4 5 6 (in billions)

Year Years elapsed

7

8

9

1804 1927 1959 1974 1987 1999 2012 2025 2040 123 32 14.75 13.25 12.25 12.33 13 15

There is currently no estimation on the exact day the world's population surpassed both the 1 and 2 billion marks. The day of 3 and 4 billion were not officially celebrated, but the International Database of the U.S. Census Bureau places them around July 1959, and April 1974. The United Nations did determine, and celebrate, the "Day of 5 billion" (July 11, 1987), and the "Day of 6 billion" (October 12, 1999). The U.S. Census bureau, International Programs division, currently estimated that the world reached 6 billion on April 21, 1999 (several months earlier than the official UN day). The "Day of 7 billion" has been targeted by the Census Bureau to be in February 2012.[32]

[edit] Years for Population to Double

Including some more estimates (together with an interpolated number for year 950), the world population has been doubled or will double in the following years (with two different starting points). Note how, during the 2nd millennium, each doubling has taken roughly half as long as the previous doubling. However, it is unlikely that there will be another doubling in the current century.[33]

Years for Population to Double Starting at 250 million Population 0.25 0.5 1 2 4 8 (in billions)

Starting at 375 million 0.375 0.75 1.5

3

6

Year 950 1600 1804 1927 1974 2025 1420 1720 1875 1959 1999 Years elapsed 650 204 123 47 51 300 155 84 40

[edit] Distribution

Population density map of the world in 1994, when the world's population was 5.6 billion; Observe the high densities in the Indo-Gangetic and North China plains, the Sichuan Basin, the Nile river delta, Southern Japan, Western Europe, Java, and the Boston-Washington corridor. Main article: Population density

Asia accounts for over 60% of the world population with almost 3.8 billion people. The People's Republic of China and India alone comprise 20% and 17% respectively. Africa follows with 840 million people, 12% of the world's population. Europe's 710 million people make up 11% of the world's population. North America is home to 514 million (8%), South America to 371 million (5.3%), and Australia to 21 million (0.3%).

[edit] The world's most populous nations Further information: List of countries and dependencies by population density and List of countries by population

Map of countries by population The 10 most densely populated countries Area Density (Pop per Rank Country Population Notes (km²) km²) [34] 1 32,719 1.95 16,779 Monaco 2 Singapore 4,620,657 707.1 6,535 [35] 3 824 0.44 1,873 Vatican City 4 385,375 298 1,293 Maldives 5 Malta 404,032 316 1,279 [36] 6 Bahrain 723,967 665 1,089 [37] 7 Bangladesh 155,688,660 147,570 1,055 Palestinian 8 4,223,760 6,020 702 territories 9 Nauru 13,918 21 663 Republic of China [35] 10 22,955,395 36,190 634 ("Taiwan")

Population by region, 2007 The 16 countries with the largest total population: Country / % of world Rank Population Date Territory population China March 25, 1 (excluding Hong 1,329,740,000 19.66% 2009 Kong and Macau) 2

India

—

European Union

1,145,174,000 499,673,300

3

United States

305,924,270

4

Indonesia

229,631,355

5

Brazil

190,765,170

6

Pakistan

166,137,500

7

Bangladesh

155,688,660

8

Nigeria

148,235,170

9

Russia

141,849,333

10

Japan

127,170,110

11

Mexico

111,077,375

March 3, 2009 January 1, 2009 March 2, 2009 March 3, 2009 March 3, 2009 April 15, 2009 March 2, 2009 March 3, 2009 March 2, 2009 March 2,

Source Chinese Population Clock[38]

16.94%

Indian Population clock

7.39%

Eurostat estimate

4.53%

Official USA Population clock

3.4%

Indonesian Population clock

2.82%

Brazilian Population clock

2.45%

Pakistani Population clock

2.3%

Private Bangladeshi Population clock

2.19%

UN estimate

2.1%

Russian Population Clock

1.88%

Japanese Statistics Bureau

1.64%

Private Mexican

2009 March 2, 93,843,460 2009 March 2, 86,709,095 2009 December 82,060,000 2008

12

Philippines

13

Vietnam

14

Germany

15

Ethiopia

79,221,000

16

Egypt

75,973,137

Population Clock

1.39%

Private Filipino Population Clock

1.28%

Private Vietnamese Population Clock

1.21%

Federal Statistical Office of Germany

July 2008

1.18%

Ethiopia Central Statistics Agency

March 3, 2009

1.12%

Egyptian Population Clock

Approximately 4.51 billion people live in these 16 countries, representing roughly twothirds (66.7%) of the world's population as of February 2009.

Countries ranking in the top 40 both in terms of total population (more than 29 million people) and population density (more than 310 people per square kilometer): Density (Pop. per Country Population Notes km²) India 1,160,139,960 352.9 Second largest country Largest fast growing Bangladesh 155,688,660 1,055.0 country Japan 127,170,110 336.5 Declining in population Philippines 93,843,460 312.8 Fast growing country South Korea 49,354,980 493.4 Steady in population

[edit] Ethnicity Main article: List of ethnic groups The world is made up of thousands of ethnic groups. The single largest ethnic group on the planet by far is Han Chinese, which represents 19.73% of the global population. For comparison 6.06% of the planet's population is of full or partial Spanish ancestry, and on a wider scale 14.2% of earth's population is of Sub-Saharan descent (those identifying as 'Black')[citation needed].

[edit] Demographics of youth According to the 2006 CIA World Factbook, around 27% of the world's population is below 15 years of age.[39]

Before adding mortality rates, the 1990s saw the greatest number of raw births worldwide, especially in the years after 1995, despite the fact that the birth rate was not as high as in the 1960s. In fact, because of the 163 million-per-year raw births after 1995, the time it took to reach the next 109 reached its fastest pace (only 12 years), as world population reached 6 billion people in 1999, when at the beginning of the decade, the reaching was designated for the year 2000, by most demographers. These people aged 9 through 18 make up these births today, and are either from the late Generation Y group, or are in the Generation Z group. 1985–1990 marked the period with the fastest yearly population change in world history. Even though the early 1960s had a greater growth rate than in the mid and late 1980s, the population change hovered around 83 million people in the five-year period, with an alltime growth change of nearly 88 million in 1990. The reason is that the world's population was greater in the mid- and late-1980s (around 5 billion) than in the early 1960s (around 3 billion), which meant that the growth rate in the 1980s was no factor on the dramatic population change. People aged 19 to 24 make up these births today, and are a part of Generation Y.

[edit] Forecast Main article: World population estimates See also: Overpopulation UN (medium variant, 2008 rev.) and U.S. Census Bureau (June 2009) estimates[40][41] UN est US est Year Diff. Diff. (billions) (billions) 2000 6.1 6.0 2010 6.9 0.8 6.8 0.8 2020 7.7 0.8 7.6 0.8 2030 8.3 0.6 8.3 0.7 2040 8.8 0.5 8.8 0.5 2050 9.1 0.3 9.3 0.5 In the long run, the future population growth of the world is difficult to predict and the UN and US Census Bureau give different estimates. Birth rates are declining slightly on average, but vary greatly between developed countries (where birth rates are often at or below replacement levels), developing countries, and different ethnicities. Death rates can change unexpectedly due to disease, wars and catastrophes, or advances in medicine. The UN itself has issued multiple projections of future world population, based on different assumptions. Over the last 10 years, the UN had consistently revised these projections downward, until the 2006 revision issued March 14, 2007 revised the 2050 mid-range estimate upwards by 273 million. The United States Census Bureau issued a revised forecast for world population that increased its projection for the year 2050 to above 9.4 billion people (which was the UN's 1996 projection for 2050), up from 9.1 billion people. A new US Census Bureau revision from June 18, 2008 has increased its projections further, to beyond 9.5 billion in 2050.

Other projections are that the world's population will eventually crest, though it is uncertain when or how. In some scenarios, it will crest as early as around 2050 at under 9 billion, or 10 to 11 billion, due to gradually decreasing birth rates.[16] In other scenarios, disasters triggered by the growing population's demand for scarce resources will eventually lead to a sudden population crash, or even a Malthusian catastrophe (also see overpopulation and food security).

Year World 2000 6,070,581 2005 6,453,628 2010 6,830,283 2015 7,197,247 2020 7,540,237 2025 7,851,455 2030 8,130,149 2035 8,378,184 2040 8,593,591 2045 8,774,394 2050 8,918,724

UN estimates (in thousands).[16][18][42] Latin US and Africa Asia Europe Oceania America Canada 795,671 3,679,737 727,986 520,229 315,915 31,043 (13.1%) (60.6%) (12.0%) (8.6%) (5.2%) (0.5%) 887,964 3,917,508 724,722 558,281 332,156 32,998 (13.8%) (60.7%) (11.2%) (8.7%) (5.1%) (0.5%) 984,225 4,148,948 719,714 594,436 348,139 34,821 (14.4%) (60.7%) (10.5%) (8.7%) (5.1%) (0.5%) 1,084,540 4,370,522 713,402 628,260 363,953 36,569 (15.1%) (60.7%) (9.9%) (8.7%) (5.1%) (0.5%) 1,187,584 4,570,131 705,410 659,248 379,589 38,275 (15.7%) (60.6%) (9.4%) (8.7%) (5.0%) (0.5%) 1,292,085 4,742,232 696,036 686,857 394,312 39,933 (16.5%) (60.4%) (8.9%) (8.7%) (5.0%) (0.5%) 1,398,004 4,886,647 685,440 711,058 407,532 41,468 (17.2%) (60.1%) (8.4%) (8.7%) (5.0%) (0.5%) 1,504,179 5,006,700 673,638 731,591 419,273 42,803 (18.0%) (59.8%) (8.0%) (8.7%) (5.0%) (0.5%) 1,608,329 5,103,021 660,645 747,953 429,706 43,938 (18.7%) (59.4%) (8.0%) (8.7%) (5.0%) (0.5%) 1,708,407 5,175,311 646,630 759,955 439,163 44,929 (19.5%) (59.0%) (7.4%) (8.7%) (5.0%) (0.5%) 1,803,298 5,217,202 653,323 767,685 447,931 45,815 (20.2%) (58.5%) (7.3%) (8.6%) (5.0%) (0.5%)

[edit] Predictions based on population growth In 1798 Thomas Malthus incorrectly predicted that population growth would outrun food supply by the mid 19th century. In 1968, Paul R. Ehrlich reprised this argument in The Population Bomb, predicting famine in the 1970s and 1980s. The dire 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 kept pace with population growth, but Malthusians point out the green revolution relies heavily on petroleum-based fertilizers, and that many crops have become so genetically uniform that a crop failure would be very widespread. Food prices in the early

21st century are rising sharply on a global scale, and causing serious malnutrition to spread widely.[43] From 1950 to 1984, as the Green Revolution transformed agriculture around the world, grain production increased by 250%. The energy for the Green Revolution was provided by fossil fuels in the form of fertilizers (natural gas), pesticides (oil), and hydrocarbonfueled irrigation.[44] The peaking of world hydrocarbon production (Peak oil) may test Malthus and Ehrlich critics.[45][46] As of May 2008, the price of grain has been pushed up by increased farming for use in biofuels,[47] world oil prices at over $140 per barrel,[48] global population growth,[49] climate change,[50] loss of agricultural land to residential and industrial development,[51][52] and growing consumer demand in China and India[53][54]. Food riots have recently occurred in many countries across the world.[55][56][57] The world population has grown by about four billion since the beginning of the Green Revolution and most believe that, without the Revolution, there would be greater famine and malnutrition than the UN presently documents (approximately 850 million people suffering from chronic malnutrition in 2005).[58]

[edit] Number of humans who have ever lived In the 1970s it was popular to believe that 75% of all the people who had ever lived were alive in the 1970s, which would have put the total number of people who ever lived as of the 1970s as less than the current number of people alive today. This view was eventually debunked as a myth.[59] A more recent estimate of the total number of people who have ever lived was prepared by Carl Haub of the Population Reference Bureau in 1995 and subsequently updated in 2002; the updated figure was approximately 106 billion.[60][61] Haub characterized this figure as an estimate which required "selecting population sizes for different points from antiquity to the present and applying assumed birth rates to each period".[61] Given an estimated global population of 6.2 billion in 2002, it could be inferred that about 6% of all people who had ever existed were alive in 2002.[60] Other estimates of the total number of people who have ever lived range approximately from 45 billion to 125 billion, with the more robust of these falling in the 90–110 billion range.[citation needed] It is difficult to estimate for the following reasons:[citation needed] •

•

The set of specific characteristics which define a human being and distinguish early Homo sapiens from earlier or related species continues to be a subject of intense research and debate. It is thus not possible to know when to begin the count, nor which hominids to include. See in this regard also Sorites paradox. Even if the scientific community reached wide consensus regarding which characteristics distinguished human beings, it would be nearly impossible to pinpoint the time of their first appearance to even the nearest millennium because the fossil record is simply too sparse. Only a few thousand fossils of early humans have been found, most no bigger than a tooth or a knucklebone. These bone fragments are used to extrapolate the population distribution of millions of early human beings spread across the continents.

•

•

Ibd

Robust statistical data only exist for the last two or three centuries. Until the late 18th century, few nations, kingdoms, or empires had ever performed an accurate census. In many early attempts, such as Ancient Egypt and in the Persian Empire the focus was on counting merely a subset of the people for purposes of taxation or military service.[62] All claims of population sizes preceding the 18th century are estimates, and thus the margin of error for the total number of humans who have ever lived should be in the billions, or even tens of billions of people. A critical item for the estimation is life expectancy. Using a figure of 20 years and the population estimates above, one can compute about 58 billion. Using a figure of 40 yields half of that. Life expectancy varies greatly when taking into account children who died within the first year of birth, a number very difficult to estimate for earlier times.