Human activity is largely to blame for the worsening water shortages in the western United States over the past half-century, a new study shows. The analysis of climate trends that influence the availability of freshwater shows that humans are responsible for 60% of the observed changes.Go read the whole thing; it's interesting.
Another effect of global warming is more bugs, not just disease-carrying bugs. When I went to Idaho last summer, there were tons of dead trees, killed by bark beetles that weren't killed by cold temperatures in the winter. The dead and dying conifers and dry weather create a forest that is essentially a explosive mixture. The forest fires will only get worse in the next few years (that is, until the fuel is all burned up).