IPAT
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[edit] Description
IPAT (I = P * A * T) describes how Population, Affluence, and Technology contribute to environmental Impact.
The equation was developed in the 1970's during the course of a debate between Barry Commoner, Paul R. Ehrlich and John Holdren. Commoner argued that environmental impacts in the United States were caused primarily by changes in its production technology following World War II, while Ehrlich and Holdren argued that all three factors were important and emphasized in particular the role of population growth.[1]
The equation aids in understanding the various factors affecting human impacts on the environment. The technology factor can be confusing, as technology can be used both to save resources, and to exploit them further. However, generally technology is used to harness energy and increases impacts (e.g., cars, pesticides, etc.).
[edit] Formula
- Where:
- I = Human Impact on the natural environment
- P = Population
- A = Affluence - consumption per capita
- T = Technology - environmental impact per unit of consumption
[edit] Interwiki links
[edit] External links
[edit] Population
- 1950-2050 World population projections from US Census
- UN World Population Prospects - The 2006 Revision - Highlights(large pdf)
- National Geographic 2001 article on the Population Forecast
[edit] Impact
[edit] References
- ↑ O'Neill et al. 2004. Population, Greenhouse Gas Emissions and Climate Change. Essay in book: Lutz W. et al (editors). 2004. The End of Population Growth in the 21st Century London: Earthscan
