The Role Of Soot In The Climate System – An Excellent Article In The Economist

The Economist, in its November 20 2010 issue. has an excellent article on soot (black carbon) and the climate titled

Pollution in the Himalayas – Time to call the sweep? – Soot gets everywhere. Even into the world’s highest mountains

Excerpts read

“….Angela Marinoni of the Institute of Atmospheric Sciences and Climate in Bologna explained to an audience at the 2nd Third Pole Environment Workshop in Kathmandu on October 27th, the high Himalayas are also under an onslaught from this sort of pollution. Even at altitudes above 5,000 metres (16,400 feet), soot is widespread. And when it lands on glaciers it accelerates their melting.

Dr Marinoni and her colleagues have been examining Himalayan soot since 2006. In that year the Nepal Climate Observatory – Pyramid, in the Khumbu valley, began a full-time study of aerosol particles, soot among them. The researchers’ initial intention was to take advantage of what they assumed would be the pristine conditions found at such high altitude (the observatory is 5,079 metres above sea level) to measure typical background conditions of the atmosphere. Instead, they were surprised to find a thick haze, loaded with soot, smothering the mountain slope. In the rainless pre-monsoon months between January and May, about one day in five saw the Khumbu valley blanketed in a dense brown cloud.

By analysing atmospheric circulation patterns, Dr Marinoni and her colleagues found that winds could bring soot and dust from as far away as Europe, the Middle East and North Africa. And if that were not bad enough, the Himalayan valleys act as chimneys, pumping pollutants from the Indian plains to the mountain peaks. Dr Marinoni estimates that the combined effect of this crud could reduce the glaciers’ ability to reflect light by 2-5% and increase the amount of melting by 12-34%.

Those suggestions are corroborated by a study led by Xu Baiqing of the Chinese Academy of Sciences’ Institute of Tibetan Plateau Research, in Beijing. His team drilled cores from the ice of five Tibetan glaciers in order to examine the past few decades’ worth of pollution. These cores show that the level of pollution, especially soot, in Himalayan glaciers correlates with emissions in Europe and South Asia.”

We have reported on several studies that document a significant role of soot (black carbon) from industrial emissions and biomass burning on the climate system; e.g. see

Soot and Climate Change – A New Article By Jacobson 2010

A Post At The Yale Forum Climate Change & The Media By Bidisha Banerjee “Black Carbon’s Grey Areas: Key Messages From A Yale Workshop”

New Paper “Black Carbon Aerosols And The Third Polar Ice Cap” By Menon Et Al 2010

New Study On The Role Of Soot Within the Climate In The Higher Latitudes And On “Global Warming”

New Paper Elevates The Role Of Black Carbon In Global Warming

Arctic Tundra Shrub Invasion And Soot Deposition: Consequences For Spring Snowmelt And Near-surface Air Temperatures

The new Economist article is another confirmation of our conclusion in the article

Pielke Sr., R., K. Beven, G. Brasseur, J. Calvert, M. Chahine, R. Dickerson, D. Entekhabi, E. Foufoula-Georgiou, H. Gupta, V. Gupta, W. Krajewski, E. Philip Krider, W. K.M. Lau, J. McDonnell,  W. Rossow,  J. Schaake, J. Smith, S. Sorooshian,  and E. Wood, 2009: Climate change: The need to consider human forcings besides greenhouse gases. Eos, Vol. 90, No. 45, 10 November 2009, 413. Copyright (2009) American Geophysical Union

where we wrote [higlighted added]

In addition to greenhouse gas emissions, other first- order human climate forcings are important to understanding the future behavior of Earth’s climate. These forcings are spatially heterogeneous and include the effect of aerosols on clouds and associated precipitation [e.g., Rosenfeld et al., 2008], the influence of aerosol deposition (e.g., black carbon (soot) [Flanner et al. 2007] and reactive nitrogen [Galloway et al., 2004]), and the role of changes in land use/land cover [e.g., Takata et al., 2009]. Among their effects is their role in altering atmospheric and ocean circulation features away from what they would be in the natural climate system [NRC, 2005].”

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