"To slow global warming, install white roofs Such roofs and reflective pavement in the world's 100 largest cities would have a massive cooling effect, according to data released at California's annual Climate Change Research Conference." - Michael Muller

Maybe CA should just spray white paint from the air, malathion-style. - Casey Muller

Good idea Casey. This white roof idea seems rather implausible though -- what fraction of the earth is covered by roofs? I would estimate approximately 0%. - Paul Buchheit

According to the paper, there are 3.8 * 10^11 square meters of "dense urban" roof, so yes, 0.07% of the earth's surface - Casey Muller

If politics are local so are energy savings: simply having a whtie roof will yield a cooler attic than having a dark roof, so money will be saved, energy for cooling will be saved. Hmm, maybe that's why all those Greek island houses are white. Or do they just get a discount on chalky whitewash? - Michael Muller

hmmmmm... what's the environmental impact of white paint? - Ryan