Updated radiative forcing estimates of four halocarbons

Abstract

There is a large discrepancy (greater than 20%) between two recently published estimates of radiative forcing of four hydrofluorocarbons (HFCs), two of which, HFC-23 and HFC-134a, are the most abundant HFCs in the atmosphere. We report an intercomparison, using two different radiative transfer methods, aimed at clarifying the forcing values for HFC-23 and HFC-134a, as well as HFC-227ea and HFC-32. The calculated global, annual mean radiative forcings differed by 12% or less and are within the expected errors in the radiative forcing estimates. Copyright 2004 by the American Geophysical Union.