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Letters to Nature
Nature 344, 529 - 531 (05 April 1990); doi:10.1038/344529a0

Relative contributions of greenhouse gas emissions to global warming

Daniel A. Lashof* & Dilip R. Ahuja

*Natural Resources Defense Council, 1350 New York Avenue, Northwest Washington, DC 20005, USA
Tata Energy Research Institute, New Delhi 110003, India
Present address: The Bruce Company, Suite 215, 1100 6th Street, Southwest Washington, DC 20024, USA

IN the past few years, many workers have noted that the combined effect on climate of increases in the concentrations of a large number of trace gases could rival or even exceed that of the increasing concentration of carbon dioxide1–3. These trace gases, principally methane, nitrous oxide and chlorofluorocarbons, are present at concentrations that are two to six orders of magnitude lower than that of carbon dioxide, but are important because, per molecule, they absorb infrared radiation much more strongly than carbon dioxide. Indeed a recent study4 shows that trace gases are responsible for 43% of the increase in radiative forcing from 1980 to 1990 (Fig. 1). An index to compare the contribution of various 'greenhouse' gas emissions to global warming is needed to develop cost-effective strategies for limiting this warming. Estimates of relative contributions to additional greenhouse forcing during particular periods do not fully take into account differences in atmospheric residence times among the important greenhouse gases. Here we extend recent work on halocarbons5,6 by proposing an index of global warming potential for methane, carbon monoxide, nitrous oxide and CFCs relative to that of carbon dioxide. We find, for example, that methane has, per mole, a global warming potential 3.7 times that of carbon dioxide. On this basis, carbon dioxide emissions account for 80% of the contribution to global warming of current greenhouse gas emissions, as compared with 57% of the increase in radiative forcing for the 1980s.



1. Lacis, A., Hansen, J., Lee, P., Mitchell, T. & Lebedeff, S. Geophys. Res. Lett. 8, 1035−1038 (1981). | ISI | ChemPort |
2. Ramanathan, V., Cicerone, R. J., Singh, H. B. & Kiehl, J. T. J. geophys. Res. 90, 5547−5566 (1985). | ISI | ChemPort |
3. Hansen, J. et al. J. geophys. Res. 93, 9341−9364 (1988). | ChemPort |
4. Hansen, J., Lacis, A. & Prather, M. J. geophys. Res. 94, 16417−16421 (1989).
5. Rogers, J. & Stephens, D. J. geophys. Res. 90, 2423−2428 (1988).
6. Fisher, D. et al. Nature 344, 513−516 (1990). | Article | ChemPort |
7. Swart, R., de Boois, H. & Vellinga, P. in The Full Range of Responses to Anticipated Climatic Change Ch. 9, 137−159 (United Nations Environment Program and The Beijer Institute, Stockholm, 1989).
8. Smith, K. & Ahuja, D. Clim. Change (in the press).
9. Noordwijk Declaration on Atmospheric Pollution and Climatic Change (Netherlands Ministry of Environment, The Hague, November 1989).
10. DeLuchi, M., Sperling, D. & Johnston, R. Transportation Fuels and the Greenhouse Effect (University of California. University Energy Research Group, UER-182, 1987).
11. Okken, P. & Kram, T. CH4 / CO-emission from fossil fuels global warming potential ESC-WR-89-12 (ECN, Petten, The Netherlands, June 1989).
12. Dickinson, R. & Cicerone, R. Nature 319, 109−114 (1986). | Article | ISI | ChemPort |
13. Wuebbles, D. The Relative Efficiency of a Number of Halocarbons for Destroying Stratospheric Ozone Report UCID-18924 (Lawrence Livermore National Laboratory, Livermore, 1981).
14. Maier-Reimer, E. & Hasselmann, K. Clim. Dyn. 2, 63−90 (1987). | Article |
15. Edmonds, J. & Wuebbles, D. A Primer on Greenhouse Gases (US Department of Energy, NBB-0083, Washington, DC, 1988).
16. Lashof, D. Clim. Change 14, 213−242 (1989). | Article | ChemPort |
17. Thompson, A. & Cicerone, R. J. geophys. Res. 91, 10853−10864 (1986). | ChemPort |
18. Lashof, D. & Tirpak, D. Policy Options for Stabilizing Global Climate Draft Report to Congress (US Environmental Protection Agency, Washington, DC, 1989).
19. Cicerone, R. & Oremland, R. Global Biogeochemical Cycles 2, 299−328 (1988). | ChemPort |
20. Prather, M. An Assessment Model for Atmospheric Composition NASA Conference Publication 3023 (NASA, Washington, DC, 1989).
21. Thompson, A. et al. Atmos. Envir. 23, 519−532 (1989). | Article | ChemPort |
22. Ramanathan, V. et al. Rev. Geophys. 25, 1441−1482 (1987). | ChemPort |
23. Okken, P. Energy Policy (in the press).

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