Paul Krugman: Points of No Return

Recently two research teams, working independently and using different methods, reached an alarming conclusion: The West Antarctic ice sheet is doomed. The sheet’s slide into the ocean, and the resulting sharp rise in sea levels, will probably happen slowly. But it’s irreversible. Even if we took drastic action to limit global warming right now, this particular process of environmental change has reached a point of no return.

Meanwhile, Senator Marco Rubio of Florida — much of whose state is now fated to sink beneath the waves — weighed in on climate change. Some readers may recall that in 2012 Mr. Rubio, asked how old he believed the earth to be, replied “I’m not a scientist, man.” This time, however, he confidently declared the overwhelming scientific consensus on climate change false, although in a later interview he was unable to cite any sources for his skepticism.