Q and A: Has the world's population distribution changed much over time?
Surprisingly, no. During the last two centuries most of the world's people lived in Asia, while relatively few lived in Latin America, North America, and Oceania. Europe ranks second to Asia, but its share is decreasing while Africa's share is increasing.
Prior to 1800, Asia's population represented roughly two-thirds of the world total. Europe and Africa fluctuated, each usually holding between 15 percent and 20 percent of the world population. The remaining few people were scattered in Latin America, North America, and Oceania, with Latin America having the largest number. By 1800, the Industrial Revolution began in Europe and its share of global population increased.
Asia maintained two-thirds of the world's people and Africa's share declined. Less than 5 percent resided in the Americas and Oceania combined (see chart, "World Population Distribution by Region, 1800–2050,"). By 1900, Asia's share of the world population declined to about one-half as Europe, North America, and Latin America grew rapidly. Since rates of population growth are currently highest in the less developed regions, their share of world population will increase. In 2000, Asia's population rose again to account for 60 percent of the world total; Africa's share increased to be equal to Europe's portion. If current trends continue, Asia will remain at 60 percent of the world total in 2050, Africa's share will rise to about 20 percent, and Europe's share will drop below Latin America's — less than 10 percent.
Over time, the distribution of population changes because of variations in the rate of natural increase and net migration. In the United States two-thirds of population growth is from natural increase and one-third is from immigration or international migration. Internal change in population distribution within the United States occurs because of internal migration rather than as a result of natural increase. Every year, nearly one in five Americans moves to a new location, making the United States one of the world's most mobile societies.
Rural-to-urban migration, combined with natural increase, is leading to a disproportionate increase in urban population, especially in less developed countries. A century ago, only 10 percent of the world's population lived in urban areas. By 1950, the urban share had risen to 29 percent, and today it is 45 percent. By the year 2020, the majority of human beings — about three-fifths — are projected to live in urban areas, ranging from market towns to megacities. Urban areas are getting larger. In 1950, only the New York urban area had over 10 million people. By 2010, there could be more than 26 urban areas over 10 million — twice the number in 1990. Five of these urban areas would hold over 20 million people each. Only two of the 10 largest urban areas projected for 2010 are expected to be in the more developed countries (see "Top 10 largest urban agglomerations", below).
Top 10 largest urban agglomerations in 1950, 2000, 2015
| 1950 |
|
2000 |
|
2015 |
| 1. New York, USA |
12.3 |
|
1. Tokyo, Japan |
26.4 |
|
1. Tokyo, Japan |
26.4 |
| 2. London, England |
8.7 |
|
2. Mexico City, Mexico |
18.4 |
|
2. Bombay, India |
26.1 |
| 3. Tokyo, Japan |
6.9 |
|
3. Bombay, India |
18.0 |
|
3. Lagos, Nigeria |
23.2 |
| 4. Paris, France |
5.4 |
|
4. São Paulo, Brazil |
17.8 |
|
4. Dhaka, Bangladesh |
21.1 |
| 5. Moscow, Russia |
5.4 |
|
5. New York, USA |
16.6 |
|
5. São Paulo, Brazil |
20.4 |
| 6. Shanghai, China |
5.3 |
|
6. Lagos, Nigeria |
13.4 |
|
6. Karachi, Pakistan |
19.2 |
| 7. Essen, Germany |
5.3 |
|
7. Los Angeles, USA |
13.1 |
|
7. Mexico City, Mexico |
19.2 |
| 8. Buenos Aires, Argentina |
5.0 |
|
8. Calcutta, India |
12.9 |
|
8. New York, USA |
17.4 |
| 9. Chicago, USA |
4.9 |
|
9. Shanghai, China |
12.9 |
|
9. Jakarta, Indonesia |
17.3 |
| 10. Calcutta, India |
4.4 |
|
10. Buenos Aires, Argentina |
12.6 |
|
10. Calcutta, India |
17.3 |
Source: United Nations, World Urbanization Prospects, The 1999 Revision.
Terms
Growth rate: The number of persons added to (or subtracted from) a population in a year due to natural increase and net migration; expressed as a percentage of the population at the beginning of the time period.
Less developed countries: Less developed countries include all countries in Africa, Asia (excluding Japan), and Latin America and the Caribbean, and the regions of Melanesia, Micronesia, and Polynesia.
More developed countries: More developed countries include all countries in Europe, North America, Australia, New Zealand, and Japan.
Net migration: The net effect of immigration and emigration on an area's population in a given time period, expressed as an increase or decrease.
Rate of natural increase: The rate at which a population is increasing (or decreasing) in a given year due to a surplus (or deficit) of births over deaths, expressed as a percentage of the base population.
Urban: Countries differ in the way they classify population as "urban" or "rural." Typically, a community or settlement with a population of 2,000 or more is considered urban. A listing of country definitions is published annually in the United Nations Demographic Yearbook.