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) 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 Impact (CO 2 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). **Emissions = Population x GDP per person What s happening with the economy (GDP per person)? What s happening with technology (emissions per unit GDP)? ** Hint: I should equal emissions Emissions = Population x GDP per person Billions 10 9 8 7 6 5 4 3 2 1 0 February 4, 2009 October 20, 2008 2000 1975 1950 1900 1850 1800-10000 -7500-5000 -2500 0 2500 ~21,000,000 1968: Garrett Hardin freaks out 1
Why? Ehrlich Hardin 68 Great Leap Forward http://esa.un.org/unpp/ -- UN World Population Prospects 2006 Lutz et al. (2001. Nature 412: 543-545). http://www.census.gov/ipc/www/idb/worldgrgraph.html How many children did your grandparents have (on average)? How many children did your parents have? 1. One 2. Two 3. Three 4. Four 5. Five 6. Six or more 1. One 2. Two 3. Three 4. Four 5. Five 6. Six or more How many children do you want to have, or how many did you have? 1. Zero or adopt 2. One 3. Two 4. Three 5. Four 6. Five 7. Six or more 2010 2
http://www.indexmundi.com/g/g.aspx?v=31&c=cd&l=en Demographic transition Afghanistan Malawi Zimbabwe India China Greece Austria Norway USA 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! 328/km 2 Population Density (#/km 2 ) 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) 3.5/km 2 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. Emissions = Population x GDP per person What s happening with GDP per person? 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 https://www.cia.gov/library/publications/the-world-factbook/index.html 3
Compare GDP with other measures 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: http://www.chrisjordan.com/ 2.5-1953 10.8-1982 3.8-2000 7.2-2008 (5.1-33.7) 15.4% US & Australia Czech Rep. & Portugal Austria China France Iceland Switzerland Sweden Norway Key World Energy Statistics 2008 http://www.iea.org/textbase/publications/free_new_desc.asp?pubs_id=1199 Emissions = Population x GDP per person What s happening with GDP per person? By 2100, population may be 50% higher, and GDP/person may be 50-500% 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. Chertow describes IPAT and its history. She mentions a major transformation in perspective. Who embraced this change? 1. Barry Commoner 2. Paul Ehrlich 3. James Speth 4. Garrett Hardin 4
This transformation argued that the burden of reducing pollution lay with 1. Curbing population 2. Transforming society 3. Technology 4. Taxes 5. Tears Good news: Energy use per unit of GDP is falling! (Our economies are becoming less energy- and carbon-intensive.) Bad news: The drop in T (technology) has not been keeping pace with increases in P (population) and A (affluence). Technological realism: If China and the U.S. keep building coal plants like crazy, IPAT suggests that carbon emissions will not fall. In your view, should we be thinking about dealing with CO 2 emissions? 1. Yes 2. No 3. Currently not sure If you answered yes, what option represents your approach to the solution? I = P*A*T 1. P 2. A 3. T 4. P & A 5. P & T 6. A & T 7. P, A, & T 5
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 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. http://www.gapminder.org/ 6