Atmospheric heating by black carbon aerosol re-evaluated

R&D: Viewed as a potential target in the global effort to reduce climate change, atmospheric black carbon particles absorb significantly less sunlight than scientists predicted, raising new questions about the impact of black carbon on atmospheric warming, an international team of researchers, including climate chemists from Boston College, report today in the latest edition of the journal Science.
   
Mathematical models and laboratory experiments used to study airborne soot particles led to projections that the absorption-boosting chemicals that coat black carbon could yield an increase in absorption by as much as a factor of two. But field studies in smoggy California cities found black carbon absorption enhancements of just 6%, suggesting that climate models may be overestimating warming by black carbon, the researchers report.
   
The surprising results highlight the early challenges in a nascent sector of climate science and could have implications for regulatory efforts to reduce the production of black carbon, or soot, by curbing the burning of fossil fuels. Still, scientists agree that black carbon in the atmosphere has a significant effect on global and regional climate, with earlier studies ranking the warming effects of black carbon particles second only to carbon dioxide gas….

Air pollution belches from a truck, shot by Zakysant and modified by F. Lamiot, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license