Black carbon elevates damage to climate

A study published in Nature Geoscience indicates black carbon or soot produced by burning coal, wood, diesel and dung elevates damage to the environment by warming the atmosphere by several times.

The researchers including atmospheric scientist V. Ramanathan from Scripps Institution of Oceanography at UC San Diego and Chemical Engineer Greg Carmichael of University of Iowa, said that the black carbon or its other forms could have contributed 60% of the current global warming effect of carbon dioxide, far greater than that of any other greenhouse gas.

•   E-mail Article
•   Printer Friendly
•   Text-Size    

Ramanatham said, “Observationally based studies such as ours are converging on the same large magnitude of black carbon heating as modeling studies from Stanford, Caltech and NASA.”

“We now have to examine if black carbon is also having a large role in the retreat of arctic sea ice and Himalayan glaciers as suggested by recent studies,” he added.

Ramanatham and Carmichael studied the data collected from satellites, aircraft and surface instruments used to study the warming effect of black carbon. They estimated black carbon’s effect on the atmosphere at 0.9 watts per square which is much higher than the estimate of between 0.2 and 0.4 watts in last year’s UN sponsored Intergovernmental Panel on Climate Change (IPCC) report.

They questioned the estimates based on computer model simulations that do not take into account the amplification of black carbon's warming effect when mixed with other aerosols such as sulfates and the altitudes at which the warming occurs.

Reportedly India and China contribute 25-35 % of black carbon in the atmosphere and around 4 Lakh people die each year due to inhaling soot particles, particularly in developing countries where people use dung and wood for cooking.

They emphasised that black carbon only remain airborne for weeks as compared to CO2 which persist for more than a century.

The researchers aimed at reducing black carbon in the atmosphere which could slow down global warming in short duration while leaving precious time to fight against climate change.

Carmichael opined that after the paper's presentation related to the need to check black carbons will make it easier to generate political and regulatory momentum toward reduction of black carbon emissions.

They also said that its reduction can only help delay and not prevent the climatic changes due to CO2 emissions.