1. IPAT I = P x A x T Impact on the environment = Population x Steve
Introduction (IPAT) Population Consumption Technology Social Justice
IPAT
I = P x A x T
Impact on the environment =
Population x Steve
Activity x Sara
Technology Yoram
David Battisti Monday

2. Introduction (IPAT) Population Consumption Technology Social Justice2 3 4 5 6 7 8 9 1
Billions -
1968: Garrett Hardin freaks out
October 20, 2008
This looks a lot like exponential growth!

3. How has the world’s population grown through history?
Introduction (IPAT) Population Consumption Technology Social Justice
How has the world’s population grown through history?

4. How has the world’s population grown through history?

5. What determines population growth?
Age structure of a population

6. What Drives Population Growth: Theories
Mortality driven:
Invention of new technologies allows lowered mortality and excess of births over deaths
People will reproduce until they come up against “positive checks” (Malthus)
Fertility driven:
Population growth forces people to create new technologies to accommodate the extra people
People are capable of limiting their fertility

7. What Drives Population Growth: Demographic Transition

8. How does population growth affect the environment?
Some adverse effects:
• Decreased habitat for other species
• Resource depletion
- Changes in land cover
- Deforestation and loss of carbon sinks
- Extinction of prey species
• Pollution
- Nitrogen from fertilizers and wastes
- Sulfur from combustion

9. What does the future look like?
Some representative Total Fertility Rates
Country
TFR 1985
TFR 2000
Rwanda
7.8
5.7
Malawi
7.4
5.3
Bangladesh
5.5
3.1
India
4.3
Mexico
3.9
2.8
USA
1.8
2.1
Japan
1.7
1.5
China
Italy
1.3
World
4.2

10. What does the future look like?

11. What does the future look like?
I = PAT:
The effects of population growth on the environment will be magnified by increases in the affluence of world populations
Therefore:
Unless A and T decline drastically, we need to bring down P—not just stop the growth, but bring it down.

12. Introduction (IPAT) Population Consumption Technology Social Justice

13. Introduction (IPAT) Population Consumption Technology Social Justice
Consumption of selected industrial raw materials compared to global population. Five of the top countries consuming industrial raw materials account for roughly 10 percent of the world's population but consume up to 50 percent of more of some of the main materials. This shows a large imbalance between these 5 nations and the other 188. ( )

14. Introduction (IPAT) Population Consumption Technology Social Justice

15. Introduction (IPAT) Population Consumption Technology Social Justice
Vaclav Smil -

16. Introduction (IPAT) Population Consumption Technology Social Justice
Steve’s rebuttal

17. Introduction (IPAT) Population Consumption Technology Social Justice
Sara’s rebuttal

18. Introduction (IPAT) Population Consumption Technology Social Justice18

19. Introduction (IPAT) Population Consumption Technology Social Justice19

20. Introduction (IPAT) Population Consumption Technology Social Justice
Population density in drylands of the World. The most densely populated dryland regions are in developing countries, and the economies in this zone are vulnerable to issues like drought. 20

21. Introduction (IPAT) Population Consumption Technology Social Justice
Desertification, risks of droughts and floods and rising sea levels could drive millions of people to migrate. A variety of reports of environmental experts, NGO's, and UN agencies warn of mass migration of 'environmental refugees', ranging between 200 million and a billion people by Even though environmental migration is not new, the fear of environmental refugees has become a real political issue. 21

22. What are the possible solutions?
Introduction (IPAT) Population Consumption Technology Social Justice
What are the possible solutions?
How do we arrive as a society/country at a solution?

23. Given what you have heard today (we will come back to this later), which alternative (for a solution) do you favor for the United States
Focus on population (P)
Focus on consumption (A)
Combination of P and A.
Wait to hear technology (T)

24. Introduction (IPAT) Population Consumption Technology Social Justice
Synthesis: Reach out