1. What is IPAT and how does it help frame environmental issues?
Introduction (IPAT) Population Consumption Technology Social Justice
What is IPAT and how does it help frame environmental issues?
What are current projections for human population growth, economic growth, & technology?
Friday: Population, Affluence or Technology (or not as simple as that)

2. IPAT Impact on the environment = Population x
Introduction (IPAT) Population Consumption Technology Social Justice
IPAT
Impact on the environment =
Population x
Activity per person (or Affluence) x
Technology (impact per activity).
I = P x A x T
How many of us are there? How much stuff are we doing? How environmentally damaging is the stuff we’re doing?
Assumes affluence = consumption

3. IPAT and climate change
Introduction (IPAT) Population Consumption Technology Social Justice
IPAT and climate change
Impact (CO2 and other GHG emissions) =
Population x
Affluence (GDP* per person) x
Technology (Emissions per unit of GDP).
I = P x A x T (now you do the units analysis**)
* Gross Domestic Product measures a country’s economic output (and income).
** Hint: I should equal emissions

4. IPAT and climate change
Introduction (IPAT) Population Consumption Technology Social Justice
IPAT and climate change
**Emissions = Population x GDP per person x emissions per unit GDP
What’s happening with population?
What’s happening with the economy (GDP per person)?
What’s happening with technology (emissions per unit GDP)?

5. IPAT and climate change
Introduction (IPAT) Population Consumption Technology Social Justice
IPAT and climate change
Emissions = Population x GDP per person x emissions per unit GDP
What’s happening with population?

6. Introduction (IPAT) Population Consumption Technology Social Justice2 3 4 5 6 7 8 9 1
Billions -
1968: Garrett Hardin freaks out
October 20, 2008
February 4, 2009
~21,000,000
This looks a lot like exponential growth!

7. Introduction (IPAT) Population Consumption Technology Social Justice
Why?
-- UN World Population Prospects 2006
Lutz et al. (2001. Nature 412: ).

8. Introduction (IPAT) Population Consumption Technology Social Justice
Ehrlich ‘68
Hardin ‘68
Great Leap Forward

9. How many children did your grandparents have (on average)?
One
Two
Three
Four
Five
Six or more

10. How many children did your parents have?
One
Two
Three
Four
Five
Six or more

11. How many children do you want to have, or how many did you have?
Zero or adopt
One
Two
Three
Four
Five
Six or more

12. Introduction (IPAT) Population Consumption Technology Social Justice
What happens next?
2010

13. Introduction (IPAT) Population Consumption Technology Social Justice
Afghanistan
Malawi
Zimbabwe
India
China
Greece
Austria
USA
Norway

14. Demographic transition
Introduction (IPAT) Population Consumption Technology Social Justice
Demographic transition
World population is still increasing, but it appears to be heading for a peak of around 9.3 billion. Why???
Coercion (Tony)? Environmental awareness? The invisible hand?
Mostly just blind luck!
China’s one child policy
Is 9 billion a lot or a little?
The UN’s range for 2300 is 2 to 36 billion!

15. Population Density (#/km2)
World population density will increase from 44.6 people/sq km in 2004 to 66 in 2050.
Ranges from Bangladesh (1045), India (336), China (138) to USA (31) and Canada (3.2)

16. From UN, The World at Six Billion
Introduction (IPAT) Population Consumption Technology Social Justice
From UN, The World at Six Billion
Of the 81.6 million people currently added to the world each year, 90+% live in the less developed regions.
Countries with population over 100 million
In 1950 (4): China, India, U.S., Russian federation
In 2000 (10), add Indonesia, Brazil, Pakistan, Bangladesh, Japan, Nigeria
In 2050 (18), add Ethiopia, Congo, Mexico, Philippines, Vietnam, Iran, Egypt, Turkey.

17. IPAT and climate change
Introduction (IPAT) Population Consumption Technology Social Justice
IPAT and climate change
Emissions = Population x GDP per person x emissions per unit GDP
What’s happening with population?
What’s happening with GDP per person?

18. Introduction (IPAT) Population Consumption Technology Social Justice
Per capita GDP
Gross Domestic Product is a measure of the size of economic activity in a country.
U.S., 2007: $45,800 GDP per capita
China, 2007: $5,400
Zimbabwe 2007: $200
In 2005, world GDP rose by ≈4-5%, so per capita GDP growth was ≈3-4%.
CIA World Factbook

19. Compare GDP with other measures
Introduction (IPAT) Population Consumption Technology Social Justice
Compare GDP with other measures
( ) 15.4%

20. Affluence ~ Consumption
Introduction (IPAT) Population Consumption Technology Social Justice
Affluence ~ Consumption
Summarize
We consume a lot, we create a lot of waste.
We are trying to reduce our consumption and our waste.
Check out this web site:

21. Introduction (IPAT) Population Consumption Technology Social Justice
US & Australia
Czech Rep. &
Portugal
China
Norway
Switzerland
Sweden
Austria
Iceland
France
Key World Energy Statistics 2008

22. Introduction (IPAT) Population Consumption Technology Social Justice
China GDP per capita: $6,800 from
India GDP per capita: $3,300
U.S. GDP per capita: $42,000

23. IPAT and climate change
Introduction (IPAT) Population Consumption Technology Social Justice
IPAT and climate change
Emissions = Population x GDP per person x emissions per unit GDP
What’s happening with population?
What’s happening with GDP per person?
By 2100, population may be 50% higher, and GDP/person may be % higher.
Yoram’s conclusion: If we’re going to reduce GHG emissions, it’s gotta be technology.
Justice, power, conflict issues will likely result in a combination of factors that will or will not result in change.

24. Chertow describes IPAT and its history
Chertow describes IPAT and its history. She mentions a major transformation in perspective. Who embraced this change?
Barry Commoner
Paul Ehrlich
James Speth
Garrett Hardin

25. This transformation ‘argued’ that the burden of reducing pollution lay with …
Curbing population
Transforming society
Technology
Taxes
Tears

26. Introduction (IPAT) Population Consumption Technology Social Justice
Good news: Energy use per unit of GDP is falling! (Our economies are becoming less energy- and carbon-intensive.)

27. Introduction (IPAT) Population Consumption Technology Social Justice
Bad news: The drop in T (technology) has not been keeping pace with increases in P (population) and A (affluence).

28. Introduction (IPAT) Population Consumption Technology Social Justice
Technological realism: If China and the U.S. keep building coal plants like crazy, IPAT suggests that carbon emissions will not fall.
It better be T!!!

29. In your view, should we be thinking about dealing with CO2 emissions?
Yes No
Currently not sure

30. If you answered yes, what option represents your approach to the solution? I = P*A*T

31. Introduction (IPAT) Population Consumption Technology Social Justice
Views on technology
Technological optimists: “Technology will save us! Wind/solar/fuel cells/nuclear/etc.”
Technological pessimists: “Technology won’t save us—we need changes in values and lifestyles.”
Technological realists: “If technology doesn’t save us, we’re not going to be saved.”
Combination

32. Summary What is IPAT and how does it help frame environmental issues?
What are current projections for human population growth, economic growth, and technology?
Stay tuned to the Friday debate on population, affluence, and technology!
Web site with time, population, life expectancy, etc.