The Easiest Way to Fight Global Warming?—Simply cleaning up soot could work wonders for the climate.

[OKIsItJustMe]

http://discovermagazine.com/2009/sep/9-the-easiest-way-to-fight-global-warming

Raw Data The Easiest Way to Fight Global Warming?

Simply cleaning up soot could work wonders for the climate.

by Peter Fairley

From the September 2009 issue, published online September 8, 2009

Discussions of climate change often make it sound as if carbon dioxide is the only villain. But climatologists have identified another, less notorious form of carbon that may be nearly as dangerous: soot. The fine, black, powdery pollutant may be responsible for the very different warming trends observed between the Northern and Southern hemispheres. If discovering yet another agent of global warming gets you down, take heart. This one may be a relatively easy target for action that will slow the progress of climate change.

Soot, which climatologists call black carbon, emanates from diesel engines, power plants, the clearing of forests or burning of fields, and open cookstoves common in developing countries. While drifting in the atmosphere or after settling on the ground, soot efficiently absorbs sunlight, warms up, and radiates heat.

Until recently, however, soot’s role in warming has been muddied by the effects of another pollutant, sulfate particles generated by coal and petroleum combustion. Unlike soot, the light-colored sulfates strongly reflect sunlight, cooling the ground below. Early climate research suggested that this effect would more than offset warming from soot. “The cooling impact of sulfate was larger, and the way sulfate interacts with the atmosphere is more straightforward, so sulfate has received more attention,” explains http://www.arcticwarming.net/node/61">Drew Shindell, an atmospheric physicist at the NASA Goddard Institute for Space Studies in New York City.

But changing pollution trends are magnifying the impact of soot. Measures controlling sulfate pollution from coal-fired power plants, initiated by industrial countries in the 1970s to combat acid rain, have reduced sulfate’s cooling effect. Over the same period, the amount of soot produced by diesel engines and other sources has continued to rise, increasing black carbon’s contribution to warming.

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