The Atmosphere-Ocean System of IMAGE 2.2. A global model approach for atmospheric concentrations, and climate and sea level projections

The AOS submodel elaborates the global concentrations of the most important greenhouse gases and ozone precursors, along with their direct and indirect effects on global-mean radiative forcing. These submodels are based on state-of-the-art approximations, as published by the Intergovernmental Panel on Climate Change (IPCC) in its Third Assessment Report (TAR).

That these simple submodels can adequately reproduce the global concentrations and forcings of more complex models in a very short runtime is also true for the simple climate submodel for calculating the consequences for the climate system and sea-level rise described in this report. We also elaborate on the scientific background and the most important features of the different submodels, comparing the results with other models and observations. Furthermore, we demonstrate that AOS adequately represents the 1970-1995 period for the main global indicators (concentrations, temperature increase and sea-level rise).