President Donald Trump’s efforts to revive coal mining have been criticized as picking winners. Actually, it’s more like picking losers: coal has become a sunset industry as cleaner energy sources rapidly get cheaper. If Mr. Trump succeeds at reversing the tide, it will come at a steep price, in both dollars and lives, most tragically for the coal miners he seeks to help. Coal carries huge nonfinancial costs. For example, incorporating the “social” cost of climate change due to methane and carbon dioxide emissions, Michael Greenstone, director of the Energy Policy Institute and Impact Lab co-director, estimates coal is more expensive than any other power source, and nuclear becomes cheaper than solar and wind.