Reshaping the Theory of Cloud Formation

Abstract
Man-made aerosols are believed to have a strong influence on cloud optical properties and albedo, with a radiative forcing opposite in sign to that exerted by greenhouse gases. The uncertainties associated with this indirect aerosol forcing are, however, very large. In their Perspective, Charlson et al. discuss recent insights into cloud formation. The results indicate that current estimates of both the magnitude and the uncertainty of indirect aerosol forcing may be too low.