According to EPA, carbon emissions from the U.S. power sector are too insignificant to warrant regulation. This is a bizarre conclusion: U.S. power sector’s emissions are around 6.5 billion tons, just below Russia’s total emissions from all sectors. To reach this conclusion, EPA has proposed a novel reading of the Clean Air Act. In EPA’s view, before it could regulate those emissions, it would first have to make a formal finding that they “cause or significantly contribute” to climate change, and (2) that this has to be judged on the basis of the sector’s percentage of total global carbon emissions. The statute doesn’t say either of those things.