A multi-data comparison of shortwave climate forcing changes

Abstract

Traditionally the Earth's reflectance has been assumed to be roughly constant, but large decadal variability, not reproduced by current climate models, has been reported lately from a variety of sources. We compare here the available data sets related to Earth's reflectance, in order to assess the observational constraints on the models. We find a consistent picture among all data sets of an albedo decreased during 1985-2000 between 2-3 and 6-7 W/m2, which is highly climatically significant. The largest discrepancy among the data sets occurs during 2000-2004, when some present an increasing reflectance trend, while CERES observations show a steady decrease of about 2 W/m2. Copyright 2005 by the American Geophysical Union.