Modelling Regional Climate Change in Southwest Germany

In its Fourth Assessment Report (AR4) the Intergovernmental Panel on Climate Change (IPCC) states that it is very likely that many land regions, especially on the Northern Hemisphere, will warm during the 21st century due to the general climate change, which itself is caused by the increase of anthropogenic greenhouse gases [7]. On the global scale the IPCC estimates that for the next two decades a warming of about 0.2○ C per decade can be expected on the basis of the SRES (Special Reports on Emission Scenarios, [11]) emission scenarios. Even if the concentrations of all greenhouse gases were kept at the year 2000 level, a further warming of about 0.1○ C per decade can be expected. For many land regions of the globe it is estimated that the annual mean temperature increase will be higher than the global mean. This variability of climatic change persists over all scales, from global to regional, and more or less for all climatological observables. On the spatial scale of global climate models (about 200 km) for example, the largest warming in Europe is likely to happen in the northern part in winter and in the Mediterranean area in summer [2]. Annual precipitation is very likely to increase in most of northern Europe and decrease in most of the Mediterranean area. In Central Europe, precipitation is likely to increase in winter but decrease in summer, but the agreement between the results of various models is quite low there. Extremes of daily precipitation are very likely to increase throughout Europe [1]; compared to Northern and Southern Europe, however, climatic change for Central Europe is more difficult to assess due to sometimes conflicting tendencies.