Soot, the black carbon that results from burning fossil fuels and biomass, is now considered the world’s second most potent climate pollutant, after carbon dioxide. Black carbon is an emission from burned fuels, primarily diesel combustion, industry and residential coal and other solid fuels, and open burning of fields and forests.
In an article, “Bounding the Role of Black Carbon in the Climate System,” published by the Journal of Geophysical Research: Atmospheres, a four-year study co-authored by an international team of scientists describes the role of black carbon in climate change. Soot is less persistent in the atmosphere than carbon dioxide, but the scientists estimate that there is 3 times as much black carbon adding to climate change than is currently used in climate modeling.
Black carbon is burned and emitted directly into the atmosphere. Significant sources include diesel engines, industrial coal, and residential wood and coal burners. The largest emissions come from the open burning of savannahs and forests. Soot is usually washed back to Earth with precipitation. Reducing black carbon emissions can help in reaching climate targets more quickly than previously thought, and might even counteract warming to some extent, says the article.