you have to sift through the floxum and jetsam of politicizing the issue in this article, but
"In general, each degree C of global temperature increase can be expected to produce:
• 5-10% changes in precipitation across many regions
• 3-10% increases in the amount of rain falling during the heaviest precipitation events
• 5-10% changes in streamflow across many river basins
• 15% decreases in the annually averaged extent of sea ice across the Arctic Ocean, with 25% decreases in the yearly minimum extent in September
• 5-15% reductions in the yields of crops as currently grown
• 200-400% increases in the area burned by wildfire in parts of the western United States
However, many other impacts remain difficult to quantify, in part because they depend on additional factors besides climate change. "
http://dels.nas.edu/resources/static...orld_final.pdf