Future Change of World Resources under SRES Climate Warming Scenarios : A Multi-model Analysis

Projections of the changes in water resources due to climate warming are critical for assessing the potential impacts of climate warming on human and natural systems. We analyse the potential changes in world water resources at annual and monthly scales by multi-model analysis using an ensemble of six General Circulation Models (GCMs), that forecast the future climate change based on a number of climate warming scenarios, which are presented in the Special Report on Emission Scenarios, (SRES). The discrepancies among GCMsare large; in some regions the change predicted by different GCMs are completely opposite. We screened the regions with high forecast consistency among the GCMs and categorized them into ncreasing, no change, and decreasing in annual runoff change through the multi-model analysis. Further detailed analyses on the monthly change are conducted in seven selected typical basins, which represent the different regions in annual change directions. The characteristics and possible causes for the changes in different basins are also discussed.