NEW YORK, Dec. 15 (UPI) -- U.S. and Chinese scientists say black soot deposited on Tibetan glaciers has contributed greatly to the retreat of the world's largest non-polar ice masses.
The research conducted by scientists from NASA and the Chinese Academy of Sciences determined the soot absorbs solar radiation and can speed glacial melting when deposited on snow in sufficient quantities.
The scientists said they discovered temperatures on the Tibetan Plateau -- sometimes called Earth's "third pole" -- have warmed by 1/2-degree Fahrenheit each decade for the past 30 years. That's about twice the rate of observed global temperature increases. The researchers said that suggests soot's warming influence on Tibetan glaciers could rival that of greenhouse gases.
"Tibet's glaciers are retreating at an alarming rate," said James Hansen, co-author of the study and director of NASA's Goddard Institute for Space Studies in New York City. "Black soot is probably responsible for as much as half of the glacial melt, and greenhouse gases are responsible for the rest."
The scientists said most soot in the region comes from diesel engines, coal-fired power plants and outdoor cooking stoves.
Junji Cao, co-author of the study, added, "During the last 20 years, the black soot concentration has increased two- to three-fold relative to its concentration in 1975.
The study appears in the Dec. 7 issue of the Proceedings of the National Academy of Sciences.
