Repair and cleaning efforts begin on a neighborhood damaged by a tornado system that destroyed homes and cut off access to utilities on Wednesday in Dayton, Ohio. (John Minchillo/AP) May 29 Tornadoes have been popping up every day in the U.S. as if coming off an assembly line. They’re part of an explosion of extreme weather events, including record flooding , record cold and record heat . Wednesday brought more of the same, with tornado watches in the Midwest and Atlantic seaboard and 37 million Americans facing an “enhanced” risk of severe weather, according to the National Weather Service . All of which raises the question: Is this climate change, or just an unusually bad year? For years, scientists have warned that climate change caused by human activity — primarily the burning of fossil fuels and the spike in atmospheric greenhouse gases — would make extreme weather events more […]