Count the soot
BLACK carbon, or soot, was known as a threat to only the public health until 2007 when the UN climate agency, IPCC, said it is a major contributor to global warming after CO2. The fine particulate matter, which efficiently absorbs sunlight and causes atmospheric warming, is released in large amounts from the combustion of fossil fuels such as diesel and coal and biomass fuel like dung and wood. Scientists from University of California in San Diego, USA, recently studied different sources of black carbon emission and suggested the net warming effect of black carbon from fossil fuel combustion has a major bearing on the global warming than black carbon from biomass fuel burning. For full text: http://www.downtoearth.org.in/node/1757