Battling a big problem like climate change will require big ideas. And scientists in the U.K. have one of the biggest: take ocean water, shoot it up into the atmosphere, and let the resulting clouds cool the earth like a massive, wet blanket. Granted, these folks are not the first to float this incredible-sounding strategy, known as "marine-cloud brightening." In one example, the physicist John Latham wrote in 1990 that the life of clouds might be prolonged by artificially increasing their "droplet concentration." These thicker clouds would reflect more of the sun's radiation away from the planet, in theory allowing...
