One very important caveat, Will: is we reduce coal emissions swiftly, there will be a short term increase in global warming, as the sulphate in the atmosphere filtered out some of the sun’s heat (which is why large volcanic eruptions lead to atmospheric cooling). Given how close we are to Climate tipping points, rapidly cutting coal could be dangerous - unless, at the same time we cut the small group of potent but short lived climate pollutants - Methane, soot, HCFCs. The best book on this: Cut Super Climate Pollutants Now! By Medium.com writer Alan Miller.