 By the 1950s, scientists had begun noticing that the planet was getting warmer. And between 1896, when he published that, and the 1950s, there were a lot of theories about it. And the first great American climate scientist, a man named Roger Revelle, he began to do work on it. And what he found was that it wasn't going to be centuries away, which is what Arrhenius had thought, that we were...