Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Black carbon is much larger cause of climate change than previously assessed

15.01.2013
Black carbon is the second largest man-made contributor to global warming and its influence on climate has been greatly underestimated, according to the first quantitative and comprehensive analysis of this pollutant’s climate impact..

The direct influence of black carbon, or soot, on warming the climate could be about twice previous estimates, according to an in-depth study published today in the Journal of Geophysical Research-Atmospheres, a publication of the American Geophysical Union.

Accounting for all of the ways black carbon can affect climate, it is believed to have a warming effect of about 1.1 Watts per square meter (W/m2), approximately two-thirds of the effect of the largest man made contributor to global warming – carbon dioxide.

“This study confirms and goes beyond other research that suggested black carbon has a strong warming effect on climate, just ahead of methane,” said co-lead author David Fahey of the U.S. National Oceanic and Atmospheric Administration (NOAA). The study, a four-year, 232-page effort, led by the International Global Atmospheric Chemistry (IGAC) Project, is likely to guide research efforts, climate modeling, and policy for years to come, the authors and other scientists familiar with the paper said..

The report’s best estimate of direct climate influence by black carbon is about a factor of two higher than most previous work. This includes the estimates in the 2007 Intergovernmental Panel on Climate Change (IPCC) Assessment, which were based on the best available evidence and analysis at that time.

Scientists have spent the years since the last IPCC assessment improving estimates, but the new assessment notes that emissions in some regions are probably higher than estimated. This is consistent with other research that also hinted at significant under-estimates in some regions’ black carbon emissions.

The results indicate that there may be a greater potential to curb warming by reducing black carbon emissions than previously thought.

“There are exciting opportunities to cool climate by reducing soot emissions but it is not straightforward,” said co-author Professor Piers Forster from the University of Leeds’s School of Earth and Environment in the United Kingdom. “Reducing emissions from diesel engines and domestic wood and coal fires is a no-brainer, as there are tandem health and climate benefits. If we did everything we could to reduce these emissions we could buy ourselves up to half a degree (Celsius) less warming--or a couple of decades of respite.”.
However, the international team urges caution because the role of black carbon in climate change is complex. “Black carbon influences climate in many ways, both directly and indirectly, and all of these effects must be considered jointly,” says co-lead author Sarah Doherty of the University of Washington in Seattle, an expert in snow measurements.

The dark particles absorb incoming and scattered heat from the sun (called solar radiation), they can promote the formation of clouds that can have either cooling or warming impact, and they can fall on the surface of snow and ice, promoting warming and increasing melting. In addition, many sources of black carbon also emit other particles that provide a cooling effect, counteracting black carbon.
The research team quantified the complexities of black carbon and the impacts of co-emitted pollutants for different sources, taking into account uncertainties in measurements and calculations. The study suggests mitigation of black carbon emissions for climate benefits must consider all emissions from each source and their complex influences on climate.

Based on the scientists’ analyses of these different sources, black carbon emission reductions targeting diesel engines and some types of wood and coal burning in small household burners would have an immediate cooling impact.

Black carbon is a significant cause of the rapid warming in the Northern Hemisphere at mid to high latitudes, including the northern United States, Canada, northern Europe and northern Asia, according to the report. The particles’ impacts can also be felt farther south, inducing changes in rainfall patterns from the Asian Monsoon. Curbing black carbon emissions could therefore have significant impact on reducing regional climate change while having a positive impact on human health by reducing the amount of damage the particles cause to the respiratory and cardiovascular systems.

“Policy makers, like the Climate and Clean Air Coalition, are talking about ways to slow global warming by reducing black carbon emissions,” said co-lead author Tami Bond of the University of Illinois at Urbana-Champaign. “This study shows that this is a viable option for some black carbon sources and since black carbon is short-lived, the impacts would be noticed immediately. Mitigating black carbon is good for curbing short-term climate change, but to really solve the long-term climate problem, carbon dioxide emissions must also be reduced.”

A note from the editors of the Journal of Geophysical Research – Atmospheres, about the significance of this article and the review process the article underwent, is available at http://bit.ly/11vqZFX

Notes for Journalists
Journalists and public information officers (PIOs) of educational and scientific institutions who have registered with AGU can download a PDF copy of this paper in press.

Or, you may order a copy of the final paper by emailing your request to Kate Ramsayer at kramsayer@agu.org. Please provide your name, the name of your publication, and your phone number.

Neither the paper nor this press release are under embargo.

Title:

“Bounding the role of black carbon in the climate system: A scientific assessment”

Authors (* indicates co-lead authors):
*Tami Bond University of Illinois at Urbana-Champaign, USA;*Sarah Doherty Joint Institute for the Study of the Atmosphere and Ocean, University of Washington, USA;*David Fahey NOAA Earth System Research Laboratory and Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, USA.*Piers Forster University of Leeds, United Kingdom;

Contact information for the authors:

Tami Bond, Telephone: +1 (217) 244-5277, Email: yark@illinois.edu

Sarah Doherty, Telephone: +1 (206) 543-6674, Email: sarahd@atmos.washington.edu

David Fahey, Telephone: +1 (303) 497-5277, Email: David.W.Fahey@noaa.gov

Piers Forster, Email: p.m.forster@leeds.ac.uk (or contact Chris Bunting, Press Officer, +44 113 343 2049 or c.j.bunting@leeds.ac.uk)

Kate Ramsayer | American Geophysical Union
Further information:
http://www.agu.org

More articles from Earth Sciences:

nachricht Impacts of mass coral die-off on Indian Ocean reefs revealed
21.02.2017 | University of Exeter

nachricht How much biomass grows in the savannah?
16.02.2017 | Friedrich-Schiller-Universität Jena

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Positrons as a new tool for lithium ion battery research: Holes in the electrode

22.02.2017 | Power and Electrical Engineering

New insights into the information processing of motor neurons

22.02.2017 | Life Sciences

Healthy Hiking in Smart Socks

22.02.2017 | Innovative Products

VideoLinks
B2B-VideoLinks
More VideoLinks >>>