Stanford researcher Mark Z. Jacobson is the latest in a line of scientists to suggest reducing soot to slow global warming. He says it is second only to carbon dioxide in its ability to warm the climate -- it's even more powerful than methane, according to his models.
He found the combination of both types of soot is the second leading cause of global warming, and that if it disappeared tomorrow, the Earth would immediately start to cool off. Average global temperatures would drop within 15 years by about 1 degree Fahrenheit, he found.
Jacobson's latest models, honed over 20 years, included the effects of black and brown soot particles that absorb solar radiation. He analyzed the impacts of soot from fossil fuels and from solid biofuels, including wood, dung and other solid biomass used in home heating and cooking in the developing world.
It wouldn't be hard to reduce soot -- particle traps on vehicles and industrial equipment would be a quick fix, Jacobson says. His work is published this week in the Journal of Geophysical Research (Atmospheres). Still, the debate is unsettled over soot's global warming potential -- a key metric for climate models.
In June, researchers from Princeton University published a study in PNAS that also assessed the climate effects of soot, and found that nations must take aggressive action to reduce it if they are to meet international climate policy goals.