Future climate warming will likely cause only minor cuts in energy output at most U.S. coal- or gas-fired power plants, a new Duke University study finds.The study — the first of its kind based on real-world data — rebuts recent modeling-based studies that warn rising temperatures will significantly lower the efficiency of power plants' cooling systems, thereby reducing plants' energy output. Those studies estimated that plant efficiencies could drop by as much as 1.3 percent for each 1 degree Celsius of climate warming.