Thursday, March 27, 2008

Black carbon contributes more in global warming: study

New York (PTI) : Black carbon, emitted from biomass burning, diesel engine exhaust and cooking fires -- widely used in India and China -- has a warming effect in the atmosphere three to four times greater than prevailing estimates, according to scientists.
In an upcoming article in the journal Nature Geoscience, Scripps Climate and Atmospheric Science Professor V Ramanathan and University of Iowa researcher Greg Carmichael presented their findings on the global warming effect that the soot and other forms of black carbon could have.
Between 25 and 35 per cent of black carbon comes from India and China, emitted from the burning of wood and cow dung in household cooking and through the use of coal to heat homes, it says.

Soot and other forms of black carbon could have as much as 60 per cent of the current global warming effect of carbon dioxide, the leading greenhouse gas, the researchers noted.

Per capita emissions of black carbon from the United States and some European countries are still comparable to those from south and east Asia, the paper says.

In the paper, Ramanathan and Carmichael integrated observed data from satellites, aircraft and surface instruments about the warming effect of black carbon.

They found that its warming effect in the atmosphere, is about 0.9 watts per metre squared (W/m-2), compared to estimates of between 0.2 W/m-2 and 0.4 W/m-2 that were agreed upon as a consensus estimate in a report released last year by the Intergovernmental Panel on Climate Change (IPCC).

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