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 = ,131,722
2004 = ,484,293
2005 = ,279,623 At 9AM Jan 18
1 birth every secs
1 death every secs
1 intnl migrant (net) every 26 secs
1 NET person every secs

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 Europe Asia & Oceania Africa Latin Am & Carib
World Resources

9. Growth to a Stable Population

10. Overshoots and Diebacks

11. Basic Causes of Environmental Problems

12. (McKinney & Schoch)

13. Environmental Impact =
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

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

17. Table 4.3
04_03.jpg

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

20. 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

21. 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.

22. Biosphere 2

24. 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

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

27. World Population Density

28. 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

29. Regional Declines in Total Fertility Rates

30. As incomes rise, so does life expectancy.

33. 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)

34. 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

35. Infant Mortality and Women's Rights

36. Birth
Control
Methods
Family Planning

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

38. 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