Reappraisal of the Climate Impacts of Ozone-Depleting Substances

A large intermodel spread in this globally averaged quantity necessitates an "emergent constraint" approach whereby we link the radiative forcing to ozone declines measured and simulated during 1979-2000, excluding two volcanically perturbed periods.

During this period, ozone-depleting substances were increasing, and several merged satellite-based climatologies document the ensuing decline of total-column ozone. Using these analyses, we find an effective radiative forcing of -0.05 to 0.13 W m(-2). Our best estimate (0.04 W m(-2)) is on the edge of the "likely" range given by the Fifth Assessment Report of IPCC of 0.03 to 0.33 W m(-2) but is in better agreement with two other literature results.