气候变化领域集成服务门户

Extremity of precipitation climate can be evaluated by the intensity of both wet and dry extremes. Here we illustrate the tendency towards more extreme precipitation climate during the 21st century in a multi-model ensemble of 32 climate model simulations from the Coupled Model Intercomparison Project Phase 5. We compare the projected changes in two climatic indices describing the extremity of precipitation climate. One index, the maximum 1-d precipitation (R1d) represents the wet and another, the maximum number of consecutive dry days (CDD), represents the dry extremes. Averaged over the globe, both indices are projected to increase, implying an overall tendency towards more extreme precipitation climate. The projected increase, in relative terms, is approximately twice as large in R1d as in CDD. Also on a regional scale, in almost all global land areas the precipitation climate is rather projected to become more than less extreme. Two thirds of these areas exhibit a more pronounced change in wet than dry extremes and slightly less than one third of the areas showing a more pronounced change in dry than wet extremes. Only over limited areas the precipitation climate shows a tendency towards less extreme conditions. In reproducing the observed mean precipitation in 1971-2000, the models tend to be too wet in dry regions and too dry in wet regions. There are not any consistent differences in the tendency towards more extreme precipitation climate among the models depending on their horizontal or vertical resolution.