IPATI = P x A x T

Impact on the environment =

Population x Steve

Activity x Sara

Technology. Yoram

David BattistiMonday

Introduction (IPAT) Population Consumption Technology Social Justice

Introduction (IPAT) Population Consumption Technology Social Justice

2

3

4

5

6

7

8

9

10

Billions

0

1

-10000 -7500 -5000 -2500 0 2500

1850

1800

19001950

1975

2000

1968: Garrett Hardin freaks out

October 20, 2008

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?

What determines population growth?

Age structure of a population

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

What Drives Population Growth:Demographic Transition

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

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 3.1

Mexico 3.9 2.8

USA 1.8 2.1

Japan 1.7 1.5

China 1.5 1.7

Italy 1.5 1.3

World 4.2 2.8

What does the future look like?

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.

Introduction (IPAT) Population Consumption Technology Social Justice

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. (http://www.grida.no/publications/vg/waste/ )

Introduction (IPAT) Population Consumption Technology Social Justice

Introduction (IPAT) Population Consumption Technology Social Justice

Vaclav Smil - http://home.cc.umanitoba.ca/~vsmil/graphics/energy/hdi.htm

Introduction (IPAT) Population Consumption Technology Social Justice

Steve’s rebuttal

Sara’s rebuttal

Introduction (IPAT) Population Consumption Technology Social Justice

Introduction (IPAT) Population Consumption Technology Social Justice

Introduction (IPAT) Population Consumption Technology Social Justice

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. http://earthtrends.wri.org/maps_spatial/maps_detail_static.php?map_select=461&theme=9

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 2050. Even though environmental migration is not new, the fear of environmental refugees has become a real political issue.

Introduction (IPAT) Population Consumption Technology Social Justice

What are the possible solutions?

How do we arrive as a society/country at a solution?

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

1 2 3 4

5%

31%

50%

14%

1. Focus on population (P)

2. Focus on consumption (A)

3. Combination of P and A.

4. Wait to hear technology (T)

Synthesis: Reach out

Introduction (IPAT) Population Consumption Technology Social Justice