Dry country

"Although the West has gone through natural wet and dry cycles in the past, the current water flow trends differ significantly in length and in strength from natural variations in the past, the researchers conclude." That's from the a summary of an article in a recent issue of Science, "Human-Induced Changes in the Hydrology of the Western United States," (pdf) where Tim Barnett of the Scripps Institute of Oceanography at the University of California at San Diego and colleagues report that "up to 60 percent of the changes in river flow, snow pack and winter air temperatures in the region during this period can be attributed to human-caused climate change."