| Comparison of Global Warming Potentials from the Second and Third Assessment Reports of the Intergovernmaental Panel on Climate Change (IPCC) |
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Global warming potentials (GWPs) are used to compare the abilities of different greenhouse gases to trap heat in the atmosphere. GWPs are based on the radiative efficiency (heat-absorbing ability) of each gas relative to that of carbon dioxide (CO2), as well as the decay rate of each gas (the amount removed from the atmosphere over a given number of years) relative to that of CO2. The GWP provides a construct for converting emissions of various gases into a common measure, which allows climate analysts to aggregate the radiative impacts of various greenhouse gases into a uniform measure denominated in carbon or carbon dioxide equivalents.
EIA has used the IPCC's revised GWPs to calculate carbon dioxide equivalents in summarizing the emissions estimates presented in Emissions of Greenhouse Gases in the United States 2004 and to assist in the analysis of the 2004 data year emissions and emission reductions reported to the Voluntary Reporting of Greenhouse Gases Program (see Voluntary Reporting of Greenhouse Gases 2004). |
| Comparison of 100-Year GWP Estimates from the IPCC's Second (1996) and Third (2001) Assessment Reports |
| Gas |
1996 IPCC GWPa |
2001 IPCC GWPb |
| Carbon Dioxide |
1 |
1 |
| Methane |
21 |
23 |
| Nitrous Oxide |
310 |
296 |
| HFC-23 |
11,700 |
12,000 |
| HFC-125 |
2,800 |
3,400 |
| HFC-134a |
1,300 |
1,300 |
| HFC-143a |
3,800 |
4,300 |
| HFC-152a |
140 |
120 |
| HFC-227ea |
2,900 |
3,500 |
| HFC-236fa |
6,300 |
9,400 |
| Perfluoromethane (CF4) |
6,500 |
5,700 |
| Perfluoroethane (C2F6) |
9,200 |
11,900 |
| Sulfur Hexafluoride (SF6) |
23,900 |
22,200 |
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a Intergovernmental Panel on Climate Change, Climate Change 1995: The Science of Climate Change (Cambridge, UK: Cambridge University Press, 1996).
b Intergovernmental Panel on Climate Change, Climate Change 2001: The Scientific Basis (Cambridge, UK: Cambridge University Press, 2001).
Contact the Voluntary Reporting of Greenhouse Gases Program |