Most U.S. nuclear power plants cost more to run than they earn. Globally, the World Nuclear Industry Status Report 2019 documents the nuclear enterprise’s slow-motion commercial collapse—dying of an incurable attack of market forces. Yet in America, strong views are held across the political spectrum on whether nuclear power is essential or merely helpful in protecting the Earth’s climate—and both those views are wrong. In fact, building new reactors, or operating most existing ones, makes climate change worse compared with spending the same money on more-climate-effective ways to deliver the same energy services. Those who state as fact that rejecting (more precisely, declining to bail out) nuclear energy would make carbon reduction much harder are in good company, but are mistaken.