Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Swedish and Indian researchers constrain the sources of climate- and health-afflicting soot pollution over South Asia

23.01.2009
A gigantic brownish haze from various burning and combustion processes is blanketing India and surrounding land and oceans during the winter season.

This soot-laden Brown Cloud is affecting South Asian climate as much or more than carbon dioxide and cause premature deaths of 100 000s annually, yet its sources have been poorly understood.

In this week's issue of Science Örjan Gustafsson and colleagues at Stockholm University and in India use a novel carbon-14 method to constrain that two-thirds of the soot particles are from biomass combustion such as in household cooking and in slash-and-burn agriculture.

Brown Clouds, covering large parts of South and East Asia, originate from burning of wood, dung and crop residue as well as from industrial processes and traffic. Previous studies had left it unclear as to the relative source contributions of biomass versus fossil fuel combustion.

Combustion-derived soot particles are key components of the Brown Cloud in Asia. The soot absorbs sunlight and thereby heats the atmosphere while cooling Earth's surface by shading. The net effect of soot on climate warming in South Asia is rivaling that of carbon dioxide.

The Swedish-Indian team managed to address the uncertainty of the soot sources by the first-ever microscale measurements of natural C-14 (half-life of 5700 years) of atmospheric soot particles intercepted on a mountain top in western India and outside SW India on the Hanimaadhoo island of the Maldives. Their results, presented in the Science article, demonstrated that the brown cloud soot was persistently about two-thirds from burning of contemporary biomass (C-14 "alive") and one-third from fossil fuel combustion (C-14 "dead").

These findings provide a direction for actions to curb emissions of Brown Clouds. Örjan Gustafsson, a professor of biogeochemistry at Stockholm University and leader of the study, says that the clear message is that efforts should not be limited to car traffic and coal-fired power plants but calls on fighting poverty and spreading India-appropriate green technology to limit emissions from small-scale biomass burning. "More households in South Asia need to be given the possibility to cook food and get heating without using open fires of wood and dung" says Gustafsson.

The rewards of decreasing soot emissions from biomass combustion may be rapid and sizeable. Globally, soot accounts for roughly half the warming potential of carbon dioxide. While carbon dioxide levels in the atmosphere respond on a sluggish 100 yr timescale to reductions in emissions, Brown Cloud soot particles only reside in the atmosphere for days-weeks raising the hope for a rapid response of the climate system.

Several additional positive effects would result from a reduction on Brown Cloud soot particle emissions. A recent report by the United Nations Environment Program, Atmospheric Brown Clouds: Regional Assessment Report with Focus on Asia (http://www.rrcap.unep.org/abc/impact/) outlines severe effects including melting of the Himalayan glaciers and weather systems becoming more extreme. The Brown Cloud is also having impact on agriculture and air quality in Asia. Henning Rodhe, a professor of chemical meteorology at Stockholm University, vice-chair of the UNEP Atmospheric Brown Cloud Program and also co-author of the Science article, states that the report finds that 340 000 people in China and India die each year from cardiovascular and respiratory diseases that can be traced to human-induced emissions of combustion particles. "The impact on health alone is a strong reason to reduce these Brown Clouds" says Rodhe.

Further information
Professor Örjan Gustafsson, Department of Applied Environmental Science and the Bert Bolin Climate Research Centre, Stockholm University orjan.gustafsson@itm.su.se or +46-70-3247317.
Professor Henning Rodhe, Department of Meteorology and the Bert Bolin Climate Research Centre, Stockholm University rodhe@misu.su.se or +46-8-164342.

Reporters may contact the AAAS-Science SciPak team at +1-202-326-6440 or scipak@aaas.org to receive an official version of the Science paper during the embargo.

Pressofficer: Maria Erlandsson; maria.erlandssson@kommunikation.su.se;
+46-70 230 88 91
For pictures: Contact Stockholm University Press Office at +46 (0)8-164090 or press@su.se

Maria Erlandsson | idw
Further information:
http://www.rrcap.unep.org/abc/impact/
http://www.su.se
http://www.vr.se

More articles from Ecology, The Environment and Conservation:

nachricht Upcycling of PET Bottles: New Ideas for Resource Cycles in Germany
25.06.2018 | Fraunhofer-Institut für Betriebsfestigkeit und Systemzuverlässigkeit LBF

nachricht Dry landscapes can increase disease transmission
20.06.2018 | Forschungsverbund Berlin e.V.

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Future electronic components to be printed like newspapers

A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.

The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

A smart safe rechargeable zinc ion battery based on sol-gel transition electrolytes

20.07.2018 | Power and Electrical Engineering

Reversing cause and effect is no trouble for quantum computers

20.07.2018 | Information Technology

Princeton-UPenn research team finds physics treasure hidden in a wallpaper pattern

20.07.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>