Climate Central: The ravages of climate change could severely hurt the ability of utilities in the 11 Western states to generate power unless they “climate proof” their power grid using renewables and energy efficiency, something they are not prepared for, according to a new study.

For nearly half of the West’s existing power plants, climate change could reduce their ability to produce electricity by up to 3 percent during an average summer and possibly up to nearly 9 percent during a decade-long drought, according to the study published Monday in the journal Nature Climate Change by researchers at Arizona State University. Coal-fired power plants in Wyoming, Utah, Arizona and Colorado are especially vulnerable, the study says.