Chertow Reading

(Ctools) Chertow, M.R. “The IPAT Equation and Its Variants; Changing Views of Technology and Environmental Impact,” Journal of Industrial Ecology, 4.4 (2001): 13-29.
http://mitpress.mit.edu/journals/pdf/jiec_4_4_13_0.pdf

• IPAT Impact = Population x Affluence x Technology
• Circa 1970
• Changing from quantifying unsustainable to sustainability
  • • Reflects change in environmental movement to technology optimism
      • Cheaper, faster AND cleaner
• Generally IPAT is credited to Ehrlich
  • Simplicity makes it a good starting point
• Helped create Factor 10 Club and Factor Four and Factor X
• Started as I = PxF (impact per capita)
  • Technology is related to F. F is related to per capita consumption, the tech to make consumption possible, and what impact that technology makes
    • Possible to hold F steady or decrease it with better tech, but Ehrlich and Holdren concluded that wasn’t a real solution
• Commoner first to use IPAT with mathematical rigor—The Closing Circle
  • Created I = Population x Economic good/population X pollutant/Economic good (amount of a particular good produced or consumed)
  • I = Pollutant
  • Concluded technology is more important than population or affluence
• Academic war between Ehrlich & Holdren and Commoner
  • E&H point out that population is a multiplier of consumption and environ damage
  • Not consistent—measuring pollution sometimes, environmental impact others
  • Commoner focuses on present time and a local focus on a given pollutant
    • Light attention to resource, heavy attention to pollution
  • E&H are more broad and less about time and space
    • Say people underestimate diminishing returns, threshold effects, synergisms, and ecosystem complexity & stability
    • Indirect effects of people (interference with ecosystems) is worse than direct effects (air pollution)
• Affluence definition
  • E&H → per capita output measure
  • Commoner→differentiate the tech used to deliver goods from the actual contribution of those goods to human welfare to separate consumption from “true affluence”
    • EX the amount of beer drank didn’t rise, but the tech used to package the beer became less environmentally friendly
  • Does increased population call for improved technology, or does technology increase the carrying capacity
• IPAT’s usefulness is debated—simple and useful in a macro way, but not well supported
• T is left—represents everything that is not P and A→unit of environmental impact per unit of economic activity T=I/PxA
• Disaggregating the effects on the environment
  • IPAT does not disaggregate enough—does not allow for interactions between PAT—use STIRPAT
• Use of IPAT in climate change is one of the most enduring forms of IPAT
• Term “sustainable development” started in 1980s
  • Way of framing a problem—we go to technology
  • Technological optimists thing human behavior will be too difficult to change
    • Must try to change technology instead
• Industrial Ecology
  • Studying how the technological society affects the environment and how technology can be channeled to environmental benefit
  • Emphasis on pollution per unit of GNP or GDP is not a satisfactory universal definition of technology
• Affluence measured as GDP per person spreads the country’s wealth out, which is not accurate, but trending upwards
• Population is also trending upwards
  • Theoretically, technology should compensate for more and more affluent people
• Viewing T as environmental impact over wealth is not accurate—there are countries with clean tech with more money, and countries with dirty tech and less money
• Factor 10 club→the need to substantially reduce global material flows
  • The current productivity of resources must be significantly increased
• Factor 4→the amount of wealth extracted from one resource can quadruple
  • Technology is not to reduce pollution or increase labor productivity but increase in resource productivity
• Factor X→proposing even higher amounts of resource productivity
  • Dematerializing, eco-efficiency, or technology