World population
The world population is the total number of humans alive on the planet Earth at a given time. As of late 2006, the world population reached 6.5 billion.[1] In line with population projections, this figure continues to grow at rates that were unprecedented prior to the 20th century, although the rate of increase has almost halved since growth rates reached their peak in 1963.
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Historical figures
Below is a table of historical population figures show in thousands.[2][3][4] The availability of historical population figures varies by region. Please see World population estimates for more figures.
| Year | World | Africa | Asia | Europe | Central & South America | Northern America* | Oceania | notes |
|---|---|---|---|---|---|---|---|---|
| 8000 BC | 5 000 | [5] | ||||||
| 1000 BC | 50 000 | [5] | ||||||
| 500 BC | 100 000 | [5] | ||||||
| 1 AD | 300 000 | [6] | ||||||
| 1000 | 310 000 | |||||||
| 1750 | 791 000 | 106 000 | 502 000 | 163 000 | 16 000 | 2 000 | 2 000 | |
| 1800 | 978 000 | 107 000 | 635 000 | 203 000 | 24 000 | 7 000 | 2 000 | |
| 1850 | 1 262 000 | 111 000 | 809 000 | 276 000 | 38 000 | 26 000 | 2 000 | |
| 1900 | 1 650 000 | 133 000 | 947 000 | 408 000 | 74 000 | 82 000 | 6 000 | |
| 1950 | 2 518 629 | 221 214 | 1 398 488 | 547 403 | 167 097 | 171 616 | 12 812 | |
| 1955 | 2 755 823 | 246 746 | 1 541 947 | 575 184 | 190 797 | 186 884 | 14 265 | |
| 1960 | 3 021 475 | 277 398 | 1 701 336 | 604 401 | 218 300 | 204 152 | 15 888 | |
| 1965 | 3 334 874 | 313 744 | 1 899 424 | 634 026 | 250 452 | 219 570 | 17 657 | |
| 1970 | 3 692 492 | 357 283 | 2 143 118 | 655 855 | 284 856 | 231 937 | 19 443 | |
| 1975 | 4 068 109 | 408 160 | 2 397 512 | 675 542 | 321 906 | 243 425 | 21 564 | |
| 1980 | 4 434 682 | 469 618 | 2 632 335 | 692 431 | 361 401 | 256 068 | 22 828 | |
| 1985 | 4 830 979 | 541 814 | 2 887 552 | 706 009 | 401 469 | 269 456 | 24 678 | |
| 1990 | 5 263 593 | 622 443 | 3 167 807 | 721 582 | 441 525 | 283 549 | 26 687 | |
| 1995 | 5 674 380 | 707 462 | 3 430 052 | 727 405 | 481 099 | 299 438 | 28 924 | |
| 2000 | 6 070 581 | 795 671 | 3 679 737 | 727 986 | 520 229 | 315 915 | 31 043 | |
| 2005 | 6 453 628 | 887 964 | 3 917 508 | 724 722 | 558 281 | 332 156 | 32 998** |
* Northern America indicates the United States and Canada.
** This figure is disputed. Please see the talk page or update the figure and cite your source.
Rate of increase
Different regions have different rates of population growth. The 20th century saw the biggest increase in the world's population in human history.
In 2000, the United Nations estimated that the world's population was then growing at the rate of 1.14% (or about 75 million people) per year[7]. According to data from the CIA's 2005-2006 World Factbooks, the world human population currently increases by 203,800 every day.[8]
Globally, the population growth rate has been steadily declining from its peak of 2.19% in 1963, but growth remains high in the Middle East and Sub-Saharan Africa.[9] In some countries there is negative population growth (ie. 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 Western Europe are also expected to encounter negative population growth due to sub-replacement fertility rates.
Population growth which exceeds the carrying capacity of an area or environment results in overpopulation. Conversely, such areas may be considered "underpopulated" if the population is not large enough to maintain an economic system (see population decline).
 Population (est.) 10,000 BC - 2000 AD. |  World population 1950–2000 |  Increase rate 1950–2000 |
Milestones
The following shows estimates of when each billion milestone was met:
| Population | 1 billion | 2 billion | 3 billion | 4 billion | 5 billion | 6 billion |
| Year | 1802 | 1928 | 1961 | 1974 | 1987 | 1999 |
| Years till next billion | 126 | 33 | 13 | 13 | 12 |
These numbers show that the world's population has tripled in 72 years, and doubled in 38 years up to the year 1999. Including some more estimates, the world population has been doubled or will double in the following years (with two different starting points). Note how, during the 2nd millennium, each doubling has taken roughly half as long as the previous doubling.
| Population | 250 million | 500 million | 1 billion | 2 billion | 4 billion | 8 billion |
| Year | AD 950 | 1600 | 1802 | 1928 | 1974 | 2028 |
| Years till next doubling | 650 | 202 | 126 | 46 | 51 |
| Population | 375 million | 750 million | 1.5 billion | 3 billion | 6 billion |
| Year | 1420 | 1720 | 1875 | 1961 | 1999 |
| Years till next doubling | 300 | 155 | 86 | 38 |
Population distribution
Asia accounts for over 60% of the world population with almost 3.8 billion people. China and India alone comprise 20% and 16% respectively. Africa follows with 840 million people, 12% of the world population. Europe's 710 million people make up 11% of the world's population. North America is home to 514 million (8%), South America to 371 million (5.3%) and Oceania to roughly 60 million** (.9%).
** This figure is disputed. Please see the talk page or update the figure and cite your source.
Demographics
According to the 2006 CIA World Factbook, 27.4% of the world's population is below 15 years old[1]. By some estimates[citation needed], there are now one billion people in the world between the ages of 15 and 24.
Forecast of world population
The future population growth of the world is difficult to predict. Birth rates are declining slightly on average, but vary greatly between developed countries (where birth rates are often at or below replacement levels) and developing countries. 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 has consistently revised these projections downward.
Current projections by the UN's Population Division, based on the 2004 revision of the World Population Prospects database [2], are as follows.
| Year | Population (billions) |
|---|---|
| 2010 | 6.8 |
| 2020 | 7.6 |
| 2030 | 8.2 |
| 2040 | 8.7 |
| 2050 | 8.9 |
Other projections of population growth predict that the world's populationwill eventually crest, though it is uncertain exactly when or how. In some scenarios, the population will crest as early as the mid-21st century at under 9 billion, due to gradually decreasing birth rates.[citation needed]
In other scenarios, disasters triggered by the growing population's demand for scarce resources will eventually lead to a sudden population crash, or even aMalthusian catastrophe (also see overpopulation).
Below is a table of predicted population figures.[3][4][5] Please see World population estimates for more figures.
| Year | World | Africa | Asia | Europe | Latin America | Northern America* | Oceania |
|---|---|---|---|---|---|---|---|
| 2010 | 6 830 283 000 | 984 225 000 | 4 148 948 000 | 719 714 000 | 594 436 000 | 348 139 000 | 34 821 000 |
| 2015 | 7 197 247 000 | 1 084 540 000 | 4 370 522 000 | 713 402 000 | 628 260 000 | 363 953 000 | 36 569 000 |
| 2020 | 7 540 237 000 | 1 187 584 000 | 4 570 131 000 | 705 410 000 | 659 248 000 | 379 589 000 | 38 275 000 |
| 2025 | 7 851 455 000 | 1 292 085 000 | 4 742 232 000 | 696 036 000 | 686 857 000 | 394 312 000 | 39 933 000 |
| 2030 | 8 130 149 000 | 1 398 004 000 | 4 886 647 000 | 685 440 000 | 711 058 000 | 407 532 000 | 41 468 000 |
| 2035 | 8 378 184 000 | 1 504 179 000 | 5 006 700 000 | 673 638 000 | 731 591 000 | 419 273 000 | 42 803 000 |
| 2040 | 8 593 591 000 | 1 608 329 000 | 5 103 021 000 | 660 645 000 | 747 953 000 | 429 706 000 | 43 938 000 |
| 2045 | 8 774 394 000 | 1 708 407 000 | 5 175 311 000 | 646 630 000 | 759 955 000 | 439 163 000 | 44 929 000 |
| 2050 | 8 918 724 000 | 1 803 298 000 | 5 217 202 000 | 653 323 000 | 767 685 000 | 447 931 000 | 45 815 000 |
* Northern America indicates the United States and Canada
Predictions based on our growing population
In 1798, Thomas Malthus predicted that population growth would eventually outrun food supply in the middle of the 19th century, resulting in catastrophe. In 1968, Paul R. Ehrlich reignited this argument with his book The Population Bomb, which helped give the issue significant attention throughout the 1960s and 1970s. The dire predictions of Ehrlich and other neo-Malthusians were vigorously challenged by a number of economists, notably Julian Simon.
On the opposite end of the spectrum there are a number of doomsayers who argue that today's low fertility rates will have severe negative consequences.[6]
Child poverty has been linked to people having children before they have the means to care for them.
More recently, some scholars have put forward the Doomsday argument applying Bayesian probability to world population to argue that the end of humanity will come sooner than we usually think (owing to toxic waste rather than to food shortages).[citation needed]
Number of humans that have ever lived
"Guesstimating the number of people ever born... requires selecting population sizes for different points from antiquity to the present and applying assumed birth rates to each period..."[7]
Also, the number may depend on the definition of "human"; does it extend to homo erectus? The australopithecine? Pre-Cretaceous mammals? Or only the modern homo sapiens? A relative lack of fossils makes the dividing line hard to draw...
According to 2002 data:[7]
- The number who have ever been born is 106,456,367,669
- The world population in mid-2002 was 6,215,000,000
- The percentage of those ever born who were living in 2002 was 5.8%
References
- ^ Age structure of the world -- 2006 CIA World Factbook
- ^ World population prospects: the 2004 revision population database
- ^ World population prospects: the 2004 revision population database
- ^ The World at Six Billion
- ^ Population Growth over Human History
- ^ The Death of the West: How Dying Populations and Immigrant Invasions Imperil Our Country and Civilization (ISBN 0-312-30259-2), by Patrick Buchanan, The Empty Cradle: How Falling Birthrates Threaten World Prosperity (ISBN 0-465-05050-6), by Longman, and Fewer: How the New Demography of Depopulation Will Shape Our Future (ISBN 1-56663-606-X), by Wattenberg
- ^ a b How Many People Have Ever Lived on Earth? by Carl Haub, 2002; calculated from a cut-off date of 50,000 years ago.
See also
- World population estimates
- List of countries by population
- List of countries by population growth rate
- Population growth
- Overpopulation
- Population control
- The Day of Six Billion
External links
- The Day of 6 Billion official homepage
- World Population Prospects. URL accessed on April 7, 2005.
- The World in Balance Transcript of two-part PBS' Nova on World Population
- BBC (1999). UN chief welcomes six billionth baby. URL accessed on March 7, 2005.
- Central Intelligence Agency (2004). CIA The World Factbook 2004. URL accessed on February 13, 2005.
- United Nations (2001). United Nations Population Information Network. URL accessed on February 13, 2005.
- United States Census Bureau (2004). Historical Estimates of World Population. URL accessed on February 13, 2005.
- PopulationData.net (2005). PopulationData.net - Information and maps about populations around the world.
- Population Reference Bureau www.prb.org - News and issues related to population.
- (French) World Population Clock (2005). WorldPopClock.com - World population clock.
- Population Counter. Real time counter..
- Population Information on population, population growth, population problems, population statistics, and population figures.
- World maps, including maps of population from Year 1 to Year 2300
Categories
Articles with unsourced statements | Population | Demography