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Italy and the Democratic Republic of the Congo (formerly Zaire) Illustrate the Demographic Divide in 2008. Source: Carl Haub and Mary Mederios Kent, 2008 World Population Data Sheet . © 2008 POPULATION REFERENCE BUREAU. Chapter 2 Outline. World Population Growth
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Italy and the Democratic Republic of the Congo (formerly Zaire) Illustrate the Demographic Divide in 2008. Source: Carl Haub and Mary Mederios Kent, 2008 World Population Data Sheet. © 2008 POPULATION REFERENCE BUREAU
Chapter 2 Outline • World Population Growth • Geographic Distribution Of The World’s Population • Global Variation In Population Size And Growth • Global Demographic Contrasts
World Population Growth • During the first 90% of human existence, the population of the world had grown only to the size of today’s New York City. • Between 1750 and 1950, the world’s population grew from 800 million to 2.5 billion. • Since 1950 it has expanded to more than six billion.
World Population Growth Through History Billions 12 11 2100 10 9 Modern Age Old 8 Iron Bronze Middle Stone Age New Stone Age Ages Age Age 7 Future 6 2000 5 4 1975 3 1950 2 1900 1 1800 Black Death — The Plague 2000 1+ million 7000 6000 5000 3000 1000 A.D. 4000 A.D. A.D. A.D. A.D. A.D. years B.C. B.C. B.C. B.C. B.C. B.C. B.C. 1 1000 2000 3000 4000 5000 Source: Population Reference Bureau; and United Nations, World Population Projections to 2100 (1998).
Why Was Early Growth Slow? • During the first 99% of human history death rates were high. • During the hunting-gathering phase, life expectancy averaged 20 years. • More than half of children born will died before 5. • The average woman who survived the reproductive years would have to bear nearly 7 children to assure 2 survived to adulthood.
Why Are More Recent Increases so Rapid? • Acceleration in population after 1750 was due to declines in the death rate that accompanied the Industrial Revolution. • People were eating better, wearing warmer clothes, bathing more often and drinking cleaner water. • Continuing population increases are due to dramatic declines in mortality without a commensurate decline in fertility.
Women of Childbearing Age and Fertility Worldwide Source: United Nations, World Population Prospects: The 2002 Revision (medium scenario), 2003.
To Slow Population Growth, Developing Countries’ Fertility Decline Must Be Rapid. Average Lifetime Births per Woman: 1800-2007 Sources: (United States) Ansley Coale and Melvin Zelnik (1963); and National Center for Health Statistics. (Bangladesh) United Nations; Demographic and Health Surveys; and other surveys
Population in Countries With Low Fertility Decline or Growth, 2002-2025 Percent Country (average number of children per woman) China (1.8) South Korea (1.4) Trinidad & Tobago (1.6) Italy (1.2) Russia (1.1) Bulgaria (1.1) Source: United Nations, World Population Prospects: The 2002 Revision (medium scenario), 2003.
Lavender - 20 and 30 millionPink –10 and 20 millionGrey - 5 and 10 million. Orange –Greater than 100 millionBlue - 50 and 100 millionGreen -40 and 50 millionYellow - 30 and 40 million
Doubling Time • The time required for a population to double if the current rate of growth continues. • The doubling time is approximately equal to 69 divided by the growth rate. • Estimate the world’s rate of growth in the year 2003 to be 1.2% per year, the doubling time is 58 years.
Redistribution of the World’s Population through Migration • Migration streams flow from rapidly growing areas into less rapidly growing ones: • Latin America and Asia to the United States • Asia to Canada • Africa and Asia to Europe • In earlier decades, as population grew dense in a region, people moved to less populated areas.
European Expansion • Europeans began to stake out the less developed areas of the world in the 15th and 16th centuries. • Before this expansion, Europeans represented 18% of the world’s population. • By the 1930s, people of European origin in Europe, North America, and Oceania accounted for 35% of the world’s population.
The Urban Revolution • As recently as 1800, less than 1% of the world’s population lived in cities of 100,000 or more. • More than 1/3 of all humans now live in cities of that size. • Urban populations grew in some countries even without industrialization, as places sprang up where goods and services were exchanged.
World Population Clock 2009 Source: Population Reference Bureau, 2009 World Population Data Sheet.