Svante Arrhenus was a little-known Swedish chemist who in the 1890s issued a remarkable warning: Keep pumping carbon dioxide into the air the way humanity has been doing since the dawn of the industrial age (around 1750), he said, and you can double the level of the heat-trapping gas in the atmosphere, raising temperatures dramatically.
Few people listened to Arrhenius then, as few people listened in the next century to others who issued the same warning, a little louder each time. TIME came late to global warming by the standards of the Swedish chemist, but early by most measures. We published...