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Some Topics Discussed

ESC110 Chapter 4. Human Populations. Some Topics Discussed. Population growth Limits to growth Human demography Demographic transition Family planning and fertility control The future of human populations. Population Growth. World population now over ?? billion. Population = Pollution??.

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Some Topics Discussed

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  1. ESC110 Chapter 4. Human Populations Some Topics Discussed • Population growth • Limits to growth • Human demography • Demographic transition • Family planning and fertility control • The future of human populations

  2. Population Growth World population now over ?? billion

  3. Population = Pollution??

  4. World pop: • 2003 = 6,271,470,983 • 2004 = 6,345,338,406 • 2005 = 6,413,322,261 At 9AM Jan 18 • US pop: • 2003 = 290,131,722 • 2004 = 292,484,293 • 2005 = 295,279,623 At 9AM Jan 18 1 birth every 8 secs 1 death every 13 secs 1 intnl migrant (net) every 26 secs 1 NET person every 12 secs http://www.census.gov/main/www/popclock.html

  5. Current Birth and Death Rates • Every second: 4 or 5 children are born, while 2 other people die • Net gain: 2.5 humans added to the world population every second • 78 million added every year

  6. Effect of Birth Rate and Death Rate on Population Size

  7. Human Population Levels Throughout History

  8. Population Growth N Amer Latin Am & Carib Europe Asia & Oceania Africa World Resources 1998-99

  9. Growth to a Stable Population

  10. Overshoots and Diebacks

  11. Basic Causes of Environmental Problems

  12. (McKinney & Schoch)

  13. P x A x T Environmental Impact = P = population density A = affluence T = technology

  14. P = number of people A = affluence or average resource-use per person T = technology or the beneficial & harmful environmental effects of the technologies used to provide & consume each unit of resource

  15. Projected Population Growth N Amer Latin Am & Carib Europe Asia & Oceania Africa

  16. Table 4.3

  17. Stabilization ratio = crude birth rate/crude death rate S&C Amer Africa Dev’g Asia Dev’d

  18. Limits to Growth Varying Perspectives • Overpopulation causes resource depletion and environmental degradation • Human ingenuity and technology will allow us to overcome any problems - more people may be beneficial • Resources are sufficient to meet everyone's needs - shortages are the result of greed, waste, and oppression

  19. Decisions on how many children to have are influenced by many factors, including culture, religion, politics, need for old-age security, and immediate family finances.

  20. Biosphere 2

  21. Human Demography • Demography - vital statistics about people, such as births and deaths Two demographic worlds • Less-developed countries represent 80% of the world population, but more than 90% of projected growth • Richer countries tend to have negative growth rates

  22. By 2050, India will probably be the world’s most populous country.

  23. World Population Density

  24. Fertility and Birth Rates • Fecundity - physical ability to reproduce • Fertility - the actual production of offspring • Crude birth rate - number of births per year per thousand people • Total fertility rate - number of children born to an average woman during her reproductive life • Zero population growth (ZPG) – occurs when births + immigration = deaths + emigration

  25. Regional Declines in Total Fertility Rates

  26. As incomes rise, so does life expectancy.

  27. Population Growth -Opposing Factors Pronatalist pressures • Factors that increase people’s desires to have children (eg, enjoy family, help earnings, high death rate, help when older, males valued, male pride, etc) Birth reduction pressures • Factors that tend to reduce fertility (eg, educated women & careers, higher family earnings, etc)

  28. Demographic Transition • Optimistic view - world population will stabilize during this century • Pessimistic view - poorer countries of the world are caught in a "demographic trap" - helping poor countries will only further threaten the earth's resources • Social justice view - overpopulation due to a lack of justice, not resources

  29. Infant Mortality and Women's Rights

  30. Birth Control Methods Family Planning

  31. The Future of Human Populations U.N. Projections

  32. Summary: • Population Doubling Times • Role of Technology • Two Demographic Worlds • Fertility and Birth Rates • Mortality and Death Rates • Population Growth Factors • Demographic Transition • Future of Population Growth

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