Friday, April 3, 2009

Black Carbon Responsible for Half of Arctic Warming

An article published  in Nature Geoscience shows that black carbon is responsible for 50 percent, Arctic warming from 1890 to 2007. The paper by Drew Shindell of the NASA Goddard Institute for Space (GISS) and Greg Faluvegi of Columbia University also notes that most of the Arctic warming occurred from 1976 to 2007.

The study is the first to quantify the Arctic’s sensitivity to black carbon emissions from various latitudes, and concludes that the Arctic responds strongly to black carbon emissions from the Northern Hemisphere mid-latitudes, where the emissions and the forcing are greatest.Black carbon is an aerosol produced from the incomplete combustion of fossil fuels and biomass and is estimated to be the second or third largest contributor to climate change. Its emissions cause damage in two ways: while in the atmosphere, the dark particulates absorb sunlight and emit it as heat; when it falls back to earth it can darken snow and ice, reducing their reflectivity and accelerating melting. Arctic warming is more than twice the observed global average surface warming above pre-industrial levels. According to another study published by Lenton, et al. in the Proceedings of the National Academy of Sciences last year, this increased warming may soon lead to the disappearance of the Arctic summer ice, which would in turn accelerate Arctic warming by exposing darker heat-absorbing water now covered by heat reflecting ice. This would also increase the risk of releasing methane and other greenhouse gases from permafrost and from methane hydrates in the ocean, which could lead to a runaway feedback process.The mission of the Institute for Governance & Sustainable Development is to promote just and sustainable societies and to protect the environment by advancing the understanding, development and implementation of effective, accountable and democratic systems of governance for sustainable development. The Institute brings together professionals from around the world who are committed to strengthening environmental law and institutions to promote sustainable development. For more information on the Institute, please visit http://igsd.org/.





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