A new study from scientists at the Lawrence Berkeley National Laboratory (Berkeley Lab), published in Nature Climate Change, has quantitatively demonstrated that black carbon—also known as soot, a pollutant emitted from power plants, diesel engines and residential cooking and heating, as well as forest fires—reduces the reflectance of snow and ice, an effect that increases the rate of global climate change.
Soot can travel great distances and settle back to earth in remote areas far from the emission source. If it deposits on snow-covered areas such as the poles or glaciers, it darkens the snow and ice, with the result that less solar radiation is reflected back into space. More heat is retained near the earth’s surface, speeding up global warming.
Although computer models of global climate have estimated this effect, the impact of soot on snow and ice albedo had not been thoroughly measured until now.