Scientific American: Black carbon, commonly described as soot, may play a larger role in global warming than previously estimated, according to a new study.
Every year in the Northern Hemisphere about 7.5 million metric tons of black carbon, the equivalent of more than 100 times Earth's total biomass, enters the air from internal combustion engines, forest fires and other sources. The fine material absorbs sunlight almost as well as carbon dioxide--a well-known greenhouse gas--and may contribute to accelerated snowmelts...