Aerosol and Clouds
Limits on climate sensitivity derived from recent satellite and surface observations
Article first published online: 13 DEC 2007
Copyright 2007 by the American Geophysical Union.
Journal of Geophysical Research: Atmospheres (1984–2012)
Volume 112, Issue D24, 27 December 2007
How to Cite
2007), Limits on climate sensitivity derived from recent satellite and surface observations, J. Geophys. Res., 112, D24S04, doi:10.1029/2007JD008740., , , , , and (
- Issue published online: 13 DEC 2007
- Article first published online: 13 DEC 2007
- Manuscript Accepted: 10 AUG 2007
- Manuscript Revised: 21 JUL 2007
- Manuscript Received: 2 APR 2007
- climate sensitivity;
- global warming;
 An analysis of satellite and surface measurements of aerosol optical depth suggests that global average of aerosol optical depth has been recently decreasing at the rate of around 0.0014/a. This decrease is nonuniform with the fastest decrease observed over the United States and Europe. The observed rate of decreasing aerosol optical depth produces the top of the atmosphere radiative forcing that is comparable to forcing due to the current rate of increasing atmospheric concentration of carbon dioxide and other greenhouse gases. Consequently, both increasing atmospheric concentration of greenhouse gases and decreasing loading of atmospheric aerosols are major contributors to the top-of-atmosphere radiative forcing. We find that the climate sensitivity is reduced by at least a factor of 2 when direct and indirect effects of decreasing aerosols are included, compared to the case where the radiative forcing is ascribed only to increases in atmospheric concentrations of carbon dioxide. We find the empirical climate sensitivity to be between 0.29 and 0.48 K/Wm−2 when aerosol direct and indirect radiative forcing is included.