Simulations of Climate Change for IPCC AR4
The following figures and animations show first results of the simulations for the IPCC Assessment Report No. 4 (AR4). The simulations have been realised at DKRZ by scientists of MPI-M and the “Model and Data” Group using the climate model ECHAM5-MPI-OM developed at MPI-M.
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The future development of the emissions determines considerably the concentrations of CO2 and other greenhouse gases that are found in the future atmosphere. A short description of the SRES scenarios is found on the last page of the Summary for Policymakers of the last IPCC report (IPCC TAR). |
Increasing concentrations of CO2 and other greenhouse gases change the radiation budget of the earth. As a consequence the global mean temperature rises. The grey curve illustrates the response of the climate model to the observed greenhouse gas concentrations; the multicolored curves show the reaction to different emission scenarios. |
The direct comparison of the projected temperature changes for the rather pessimistic scenario A2 with those for the much more optimistic scenario B1 illustrates the variety of possible future developments. According to the new simulations a mean global warming between 2.5 and 4.1 degrees Celsius until the end of this century (relative to the mean temperature between 1961-1990) is expected - dependent on how much greenhouse gases are emitted into the atmosphere during that time.
As a consequences the seasonal varying sea ice decreases. If emissions will not be reduced, the arctic could become ice free during late summer till the end of this century ...