Global warming will bring troubled times to the Gulf Coast in the next 50 to 100 years, according to a study released yesterday by the Union of Concerned Scientists and the Ecological Society of America. The report predicts flooding, droughts, and shortages of fresh water from Laguna Madre to the Florida Keys. Rising sea levels will cause problems in a region that is already overdeveloped, and freshwater will be in short supply, as salt water creeps into coastal estuaries and evaporation increases off of reservoirs and rivers. Biologist Evan Siemann, one of the authors of the report, says he hopes it will serve as a call to action: "We need to start thinking about these things now and not wait until it’s a crisis."