"Because of a lack of action to reduce carbon dioxide emissions, the policy community is asking what else we can do, particularly to help places like the Arctic that are melting much more quickly than we had anticipated," Doherty said. "We hope reducing black-carbon emissions buys us some time. But it doesn't replace cutting back on CO2 emissions."
While carbon dioxide has a half-life of 100 years, black carbon stays in the atmosphere for only a few days.
The authors investigated various sources of black carbon to see which reductions might have the most short-term cooling impact. Regulating emissions from diesel engines followed by replacing some wood- and coal-burning household stoves, authors find, would have the greatest immediate cooling impact.
"If you're just thinking about impact on climate, you would want to be strategic about which sources you cut back on," Doherty said. "We looked at the overall impact because some of these sources also emit associated particles that can have counteracting effects."
Black carbon contributes to climate change in the mid to high latitudes, including the northern United States, Canada, northern Europe and northern Asia, as well as affecting rainfall patterns of the Asian Monsoon.
The report incorporates data that Doherty and co-author Stephen Warren, a UW professor of atmospheric sciences, gathered between 2007 and 2009 to measure soot on Arctic snow. Calculating black carbon deposits in the Arctic is difficult, so data are essential for testing and correcting models.
First author Tami Bond, now at the University of Illinois, earned a doctoral degree at the UW in 2000 that combined engineering, chemistry and atmospheric science to measure emissions from burning that have atmospheric importance.
"Mitigating black carbon is good for curbing short-term climate change, but to really solve the long-term climate problem, carbon dioxide emissions must
|Contact: Hannah Hickey|
University of Washington