© 2006 Population Reference Bureau World population growth
© 2006 Population Reference Bureau A.D A.D A.D B.C B.C B.C B.C B.C B.C B.C. 1+ million years Old Stone Age New Stone Age Bronze Age Iron Age Middle Ages Modern Age Black Death—The Plague A.D A.D A.D Future Billions Source: Population Reference Bureau; and United Nations, World Population Projections to 2100 (1998). World Population Growth Through History
© 2006 Population Reference Bureau Why is world population growing so fast? Compare life today with conditions 100 years ago: Agriculture Medicine Sanitation Health care Transportation More people reach child-bearing age and have children
© 2006 Population Reference Bureau Factors that limit population growth Famine Disease War
© 2006 Population Reference Bureau Trends in Population Growth Worldwide Population Increase and Growth Rate, Five-Year Periods Millions Percent increase per year Source: United Nations, World Population Prospects: The 2004 Revision (medium scenario), 2005.
© 2006 Population Reference Bureau Billions Less Developed Regions More Developed Regions Source: United Nations, World Population Prospects: The 2004 Revision (medium scenario), Growth in More, Less Developed Countries
© 2006 Population Reference Bureau Africa and Other Developing Regions Make Up an Increasing Share of World Population
© 2006 Population Reference Bureau Less developed countries
© 2006 Population Reference Bureau More developed countries
© 2006 Population Reference Bureau population pyramids: graphically display a population's age and gender composition; are bar graphs; show numbers or proportions of males and females in each age group; show gains of cohort members due to immigration and birth, and loss of cohort members due to emigration and death; and reflect population growth or decline.
© 2006 Population Reference Bureau Population Structures by Age and Sex, 2005 Millions Less Developed Regions More Developed Regions MaleFemaleMaleFemale Age Source: United Nations, World Population Prospects: The 2004 Revision, Age Distribution of the World’s Population
© 2006 Population Reference Bureau Less developed countries have significantly younger populations. Almost 1/3 of the population in less developed countries is under age billion young people under age 20 in less developed regions. In contrast, less than 1/5 of the population in more developed countries is under age 15. Notes on Age Distribution of the World’s Population
© 2006 Population Reference Bureau Population Demography - The study of size, birth, and death rates, and distribution of humans Adding to a human population: –Birth rate and immigration Subtracting from a human population: –Death rate and emigration Birth rates haven't increased much in our world, but death rates have become much lower in the past century.
© 2006 Population Reference Bureau Lowest and Highest Infant Mortality Rates
© 2006 Population Reference Bureau