1. Population In billions Years elapsed between milestones
Do Now: Based on the chart below, why do you think the human population has risen so drastically?
Population In billions 1 2 3 4 5 6 7 8 9
Year
1804
1927
1960
1974
1987
1999
2012
2027
2046
Years elapsed between milestones
123 33 14 13 12 15 19

2. Aim: How Many People Can the Earth Support?
Concept 6-1 We do not know how long we can continue increasing the earth’s carrying capacity for humans without seriously degrading the life-support system that keeps us and many other species alive.

3. Core Case Study: Slowing Population Growth in China: A Success Story
1.3 billion people
Promotes one-child families
Contraception, abortion, sterilization
Fast-growing economy
Serious resource and environmental problems

4. Crowded Street in China
Figure 6.1: Hundreds of people crowd a street in China. Almost one of every five persons on the planet lives in China, and the country’s resource use per person is projected to grow rapidly as China becomes more modernized and wealthy.
Fig. 6-1, p. 125

5. Human Population Growth Continues but It Is Unevenly Distributed (1)
Reasons for human population increase
Movement into new habitats and climate zones
Early and modern agriculture methods
Control of infectious diseases through
Sanitation systems
Antibiotics
Vaccines
Health care
Most population growth over last 100 years due to drop in death rates

6. Human Population Growth Continues but It Is Unevenly Distributed (2)
Population growth in developing countries is increasing 9 times faster than developed countries
2050
95% of growth in developing countries
billion people
Should the optimum sustainable population be based on cultural carrying capacity?

7. Do you understand why the population is unevenly distributed?

8. Human Population Growth
Figure 1.18: Exponential growth: The J-shaped curve represents past exponential world population growth, with projections to 2100 showing possible population stabilization as the J-shaped curve of growth changes to an S-shaped curve. (This figure is not to scale.) (Data from the World Bank and United Nations, 2008; photo L. Yong/UNEP/Peter Arnold, Inc.)
Fig. 1-18, p. 21

9. Population Time Line: 10,000 BC - 2042
Figure 3, Supplement 9

10. Annual Growth Rate of World Population, 1950-2010
6-2
Fig. 6-2, p. 127

11. Where Population Growth Occurred, 1950-2010
Figure 6.3: Most of the world’s population growth between 1950 and 2010 took place in the world’s less-developed countries. This gap is projected to increase between 2010 and (Data from United Nations Population Division, The 2008 Revision and Population Reference Bureau, 2010 World Population Data Sheet)
Fig. 6-3, p. 127

12. Five Most Populous Countries, 2010 and 2050
Figure 6.4: This chart shows the populations of the world’s five most populous countries in 2010 and 2050 (projected). In 2010, more than one of every three persons on the earth lived in China (with 19% of the world’s population) or India (with 17%). (Data from United Nations Population Division)
Fig. 6-4, p. 127

13. World population (in billions)11
UN high-fertility variant (2008 revision)
U.S. Census Bureau (2008 update) 10
UN medium-fertility variant (2008 revision)
IIASA (2007 update)
UN low-fertility variant (2008 revision)
World population (in billions) 9 8 7
Figure 6.A: This graph shows world population projections to 2050 from three different organizations: the UN, the U.S. Census Bureau, and IIASA. Note that the upper-most, middle, and lower-most curves of these five projections are all from the UN, each assuming a different level of fertility. 6
2010
2020
2030
2040
2050
Year
Fig. 6-A, p. 128

15. Science Focus: Projecting Population Change
Why range of billion for 2050?
Demographers must:
Determine reliability of current estimates
Make assumptions about fertility trends
Deal with different databases and sets of assumptions

16. World Population Projections to 2050
Figure 6.A: This graph shows world population projections to 2050 from three different organizations: the UN, the U.S. Census Bureau, and IIASA. Note that the upper-most, middle, and lower-most curves of these five projections are all from the UN, each assuming a different level of fertility.
Fig. 6-A, p. 128

17. Science Focus: How Long Can The Human Population Keep Growing?
Thomas Malthus and population growth: 1798
Overpopulation and overconsumption
Will technology increase human carrying capacity?
Can the human population grow indefinitely?

18. Natural Capital Degradation: Altering Nature to Meet Our Needs
Figure 6.B: This list describes eight major ways in which we humans have altered natural systems to meet our growing population’s resource needs and wants (Concept 6-1). See an animation based on this figure at CengageNOW. Questions: Which three of these impacts do you believe have been the most harmful? Explain. How does your lifestyle contribute directly or indirectly to each of these harmful impacts?
Fig. 6-B, p. 129

19. Summary:
Nat Geo: Are you a typical human?