Yahoo! News - Scientists Blame Soot for Global Warming

"NASA scientists say soot, mostly from diesel engines, is causing as much as a quarter of all observed global warming by reducing the ability of snow and ice to reflect sunlight.

Their findings on how soot affects reflective ability, known as albedo, raise new questions about human-caused climate change from the Arctic to the Alps.

'We suggest that soot contributes to near worldwide melting of ice that is usually attributed solely to global warming,' National Aeronautics and Space Administration scientists James Hansen and Larissa Nazarenko wrote in a paper published Monday in the Proceedings of the National Academy of Sciences ."

Lots of Bubbas, especially Bubbas in Europe, claim that diesel combustion is "cleaner" than gasoline because there is less carbon dioxide emitted. Everyone takes for granted that carbon dioxide is the major contributor to the greenhouse effect.

Still, I've never been comfortable with the idea that diesel is somehow "cleaner". When you drive behind a diesel car, you know it because it stinks. There's an organic chemical smell to it. My wife says that diesel combustion produces important amounts of benzene, which is cancer-causing.

But most of all, a diesel engine puts out important quantities of ugly black soot. This stuff is nasty enough, blackening the buildings close to any major throughway. But now add to it the change in reflective capacity of snow and you've got one real loser of a combination. I'm hoping that this will prompt the European governments to end their long-standing relative subsidies of diesel over gasoline. Of course, here in France, we can expect the highways to be blocked by trucking interests but c'est la vie!