LA Times: Black carbon pollution, or soot, produced by burning wood, coal, cow dung and diesel fuel, may be a much greater contributor to global warming than previously suspected, according to a study released this week. The report concludes that the atmospheric warming effect of black carbon pollution is as much as three to four times the consensus estimate released last year in a report by the U.N.-sponsored Intergovernmental Panel on Climate Change. The findings are of concern to …