claim: "The Keeling curve, which is widely used to show the increase in CO2 emissions, is based on data from the top of Mount Mauna Loa in Hawaii.
evidence: According to the League of Conservation Voters in 2015, the Clean Power Plan "established the first national limits on carbon pollution from existing power plants—our nation's single largest source of the pollution fueling climate change" and was "the biggest step" the United States had "ever taken to address climate change."