United Press International: Global warming will cause a risk of water shortages in two-thirds of U.S. counties by 2050, an environmental group warns. The Natural Resources Defense Council says more than a thousand counties in 14 states will probably see limitations on water availability and use as demand exceeds supply in mid-century, USA Today reported Tuesday. The high-risk areas include parts of Arizona, Arkansas, California, Colorado, Florida, Idaho, Kansas, Mississippi, Montana, Nebraska, Nevada, New …