I just wanted to alert Grist readers to an excellent post at The Oil Drum called "Fire and Rain: The Consequences of Changing Climate on Rainfall, Wildfire and Agriculture." The author points out that "Current climate change predictions for much of the West show increased precipitation in the winter or spring, along with earlier and drier summers." To summarize his post, the drier summers will have profound impacts on the forests, grasslands, and agricultural areas.
It seems that many kinds of trees are very delicately attuned to particular patterns of precipitation and temperature; changes lead to weakening, disease, and then "megafires" that are much more destructive than "normal" fires. The author discusses the biggest fires in American history, over 100 years ago, that seem to have been caused by the massive deforestation then occurring. A question I have is, is the dessication of the American West similar to the accelerating dessication of the Amazon, both the result of deforestation?
The post also discusses the plight of agricultural areas; basically, you're damned if you depend on rainfall that will be decreasing during the summer, and you're damned if you depend on irrigation, because the aquifers and mountain ice packs are decreasing. He details the effects on grains and other agricultural produce. I didn't know that potatoes, orchards, and vegetables all depend on irrigation for most of their water needs.
I realize that modeling the long-term behavior of the climate is hard enough, but it seems to me that it would be important to model the effects of those changes on our local ecosystems as well.