1. Environmental Science: Toward a Sustainable Future Richard T. Wright
Chapter 5
The Human Population: Dimensions
PPT by Clark E. Adams

2. Human Population Growth and the Consequences
Human population expansion and its cause
Different worlds
Consequences of population growth and affluence
Dynamics of population growth

3. Human Population Expansion and Its Cause
Reasons for the patterns of growth
Biotic potential exceeds environmental resistance: birth rates exceed death rates
There are 6.3 billion people on Earth
If each one stood up, pronounced their name, and sat down
It would take 600 years to complete roll call
By 2025 it will take 1,000 years to complete this exercise

4. World Population over the Centuries
9,000 human beings added to the
planet every hour

5. Reasons for the Human Population Explosion
Causes of disease recognized
Improvements in nutrition
Discovery of antibiotics
Improvements in medicine
Increase in number of women who actually reach child-bearing age
Short doubling times in some countries

6. Changing Human Survivorship Curves: Went from B to A
% Survival B
Birth
Age
Death

7. World Population Growth and Absolute Growth

8. Population Projections Based on Different Fertility Assumptions

9. Average Number of Children, Grandchildren, and Great Grandchildren
America
West Germany
Africa 14 5
258

10. Different Worlds Rich nations, poor nations
Population growth in rich and poor nations
Different populations, different problems

11. Human Poverty Index for Developing Countries

12. Economic Categories Based on Per Capita Gross National Income (see Fig
High-income, highly developed, industrialized countries
United States, Japan, Canada
Average GNI per capita = $26,710
Middle-income, moderately developed countries
Latin America, South Africa, China
Average GNI per capita = $1,850

13. Economic Categories Based on Per Capita Gross National Income (see Fig
Low-income, developing countries
Western and central Africa, India, central Asia
Average GNI per capita = $430

14. Disparities Developed countries Low-income developing countries
16% of the world’s population
Control 81% of the world’s wealth
Low-income developing countries
41% of the world’s population
Control 3.4% of the world’s gross national income
Difference in per capita income: 62 to 1!

15. Population Increase in Developed and Developing Countries

16. Population Data for Selected Countries (Table 5-3)
Country
Total Fertility Rate
Doubling Time (Years)
World
2.8 54
Developing Countries
3.5 37
Developed Countries
1.5
700

17. Different Populations, Different Problems
Human pressure on the environment caused by three factors
Population size
Affluence
Technology

18. Ecological Footprints by World Region
The average American places at least 20 times the demand on Earth’s resources as does an average person in Bangladesh
Fig. 5.7 here

19. Global Conditions for a Sustainable Population
Lower fertility rates (stabilize population)
Consumption must decrease
Protect the environment (stewardly action must increase)

20. Consequences of Population Growth and Affluence
The developing countries
Affluence

21. Developing or Developed Nations?
High fertility rates
High consumptive lifestyles: use 80% of world’s wealth
Intense poverty
Eat high on the food chain

22. Developing or Developed Nations?
Long doubling times
High environmental degradation
Twenty percent of the world’s population

23. Basic Human Needs Drinkable Water Edible Food Safe Housing Health Care
An Education
A Job

24. The Developing Countries
Reform the system of land ownership
Intensify cultivation of existing land to increase production per unit area
Open new land to farm
Move to cities and seek employment
Engage in illicit activities for income
Move to other countries
How do these “solutions” aggravate the problems?

25. Growing Cities

26. Consequences of Exploding Populations in the Developing World

27. Consequences of Exploding Populations
deforestation
resource depletion
loss of agricultural land
biodiversity
disease
pest resistance
population migration
irrigation
wetlands
MORE
More Population
Causes
LESS

28. Affluence in the United States
Consume the largest share of 11 of 20 major commodities
Eat more than three times the global average in meat
Lead the world in paper consumption
Environment improves with increasing affluence

29. Affluence in the United States
Enables wealthy to clean up immediate environment by transferring waste to more distant locations.
Affluent isolate themselves and unaware of the environmental stresses caused by their consumptive lifestyles.

30. Dynamics of Population Growth
Population profiles
Future populations
Population momentum
The demographic transition

31. Population Profiles of the United States

33. Population Profile for United States
Note increasing elderly
population.

34. Future World Populations

35. Future United States Populations

36. Projecting Future Populations: Developed Countries

37. Population Projections: Developing Nations

38. Comparing Projected Populations (see Fig. 5-17)
Fertility Rate
< 2
Fertility Rate
> 2

39. Population Momentum
Countries like Iraq will continue to grow for 50–60 years even after the total fertility rate is reduced to replacement level.

40. The Demographic Transition

41. Calculating Fertility Rates and Doubling Times
(CBR – CDR)/10 = Rate of increase or decrease
in population per 1,000 per year
70/Rate of Increase = Doubling Time

42. Calculating Fertility Rates and Doubling Times: Practice (see Table 5-5)

43. Demographic Transition Comparisons

44. By the Year 2000
65 out of 117 countries will not be able to feed their own people
One billion people will be living in cities that cannot support its inhabitants
400 million more women will be in need of child spacing services

45. By the Year 2000 (continued)
600 million new jobs will need to be created for new entrants into the workforce
We will need twice as much fresh water
300 million additional children will need teachers, books, and classrooms

46. End of Chapter 5