Soot seen as significant in global warming

PALO ALTO, Calif., July 28 (UPI) -- Soot from burning fossil fuels and solid biofuels has a greater impact on global warming than previously believed, a U.S. researcher says.

But unlike carbon dioxide, Stanford University scientist Mark Z. Jacobson says, soot stays in the atmosphere for only a few weeks, so cutting soot emissions could have a rapid and significant impact on the climate, a university release said Wednesday.

Jacobson says computer models to date have missed soot's effect on the climate, especially arctic warming, and soot has been ignored in national and international global warming policy legislation.

Jacobson's says his computer modeling shows soot is the second-leading cause of global warming after carbon dioxide, putting the effects of soot ahead of methane, a significant greenhouse gas.

"Controlling soot may be the only method of significantly slowing Arctic warming within the next two decades," said Jacobson, director of Stanford's Atmosphere/Energy Program. "We have to start taking its effects into account in planning our mitigation efforts and the sooner we start making changes, the better."

The magnitude of soot's effect, combined with the fact it is quickly washed out of the atmosphere, means a reduction in soot output would start slowing the pace of global warming almost immediately, Jacobson says.