California’s soot pollution is mostly from Asia

“More than three-quarters of the West Coast’s particulate pollution in the spring is transported at high altitudes from Asian sources as soot from black carbon, according to a research team led by Professor V. Ramanathan at Scripps Institution of Oceanography, UC San Diego… The Asian pollution is increasing global warming researchers said, calling it a “startling finding” because of the disproportional impact that black carbon has on regional climate. ‘The soot heating of the atmosphere exceeds the surface dimming and as a result the long range transported soot amplifies the global warming due to increase in carbon dioxide,’ said Ramanathan. ‘We have to find out if this amplification is just restricted to spring time or is happening throughout the year.’ Researchers say that transported black carbon from Asian sources is equal to 77 percent of North American black carbon emissions in the troposphere during the spring. They will do a follow-up study to discover what effect the Asian black carbon is having on melt rates of the Sierra Nevada snow pack.”