Atlantic: Not long ago, my newspaper informed me that glaciers in the western Antarctic, undermined by the warmer seas of a hotter world, were collapsing, and their disappearance now appears to be unstoppable. The melting of these great ice sheets would make seas rise by at least four feetultimately, possibly 12more than enough to flood cities from New York to Tokyo to Mumbai. Because I am interested in science, I read the two journal articles that had inspired the story. How much time do we have, I wondered,...