Dotted with “death villages” where crops will not fruit, the region of Inner Mongolia where the Bayan Obo mine is located displays Chernobylesque cancer rates. But then again, the death villages are already here. More of them are coming if we don’t do something about climate change. What matter is a dozen death villages when half the earth may be rendered uninhabitable? What matter the gray skies over Inner Mongolia if the alternative is turning the sky an endless white with sulfuric aerosols, as last-ditch geoengineering scenarios imagine? Moralists, armchair philosophers, and lesser-evilists may try to convince you that these situations resolve into a sort of trolley-car problem: do nothing and the trolley speeds down the track toward mass death. Do something, and you switch the trolley onto a track where fewer people die, but where you are more actively responsible for their deaths. When the survival of millions or even billions hangs in the balance, as it surely does when it comes to climate change, a few dozen death villages might seem a particularly good deal, a green deal, a new deal. But climate change doesn’t resolve into a single trolley-car problem. Rather, it’s a planet-spanning tangle of switchyards, with mass death on every track.