Also, see below the “Continue reading” line for an impressive scientific visualization video of black carbon being transported around the globe.
University of Iowa News Release July 27, 2010
UI researcher finds black carbon implicated in global warming
Increasing the ratio of black carbon to sulphate in the atmosphere increases climate warming, suggests a study conducted by a University of Iowa professor and his colleagues and published in the July 25 issue of the journal Nature Geoscience. No paper was provided with the press release.
Black carbons — arising from such sources as diesel engine exhaust and cooking fires — are widely considered a factor in global warming and are an important component of air pollution around the world, according to Greg Carmichael, Karl Kammermeyer Professor of Chemical and Biochemical Engineering in the UI College of Engineering and co-director of the UI’s Center for Global and Regional Environmental Research. Sulfates occur in the atmosphere largely as a result of various industrial processes.
Carmichael’s colleagues in the study were V. Ramanathan and Y. Feng of Scripps Institution of Oceanography, La Jolla, Calif.; S-C. Yoon and S-W. Kim of Seoul National University, South Korea; and J. J. Schauer of the University of Wisconsin, Madison.
In order to conduct their study, the researchers made ground-level studies of air samples at Cheju Island, South Korea, and then sampled the air at altitudes between 100 and 15,000 feet above the ground using unmanned aircrafts (UAVs).
They found that the amount of solar radiation absorbed increased as the black carbon to sulphate ratio rose. Also, black carbon plumes derived from fossil fuels were 100 percent more efficient at warming than were plumes arising from biomass burning.
“These results had been indicated by theory but not verified by observations before this work,” Carmichael said. “There is currently great interest in developing strategies to reduce black carbon as it offers the opportunity to reduce air pollution and global warming at the same time.”
The authors suggest that climate mitigation policies should aim to reduce the ratio of black carbon to sulphate in emissions, as well as the total amount of black carbon released.
In a paper published in May 2008 in Nature Geoscience, Carmichael and Ramanathan found that black carbon soot from diesel engine exhaust and cooking fires — widely used in Asia — may play a larger role than previously thought in global warming. They said that coal and cow dung-fueled cooking fires in China and India produce about one-third of black carbon; the rest is largely due to diesel exhaust in Europe and other regions relying on diesel transport. The paper also noted that soot and other forms of black carbon could equal up to 60 percent of the current global warming effect of carbon dioxide, the leading greenhouse gas.
Carmichael is chair of the scientific advisory group for the World Meteorological Organization’s GURME (Global atmospheric watch Urban Research Meteorology and Environment) project and chair of the scientific advisory group for the Shanghai Expo pilot project on air quality forecasting. He has worked with Shanghai authorities for three years to help develop an early warning system for air quality problems and heat waves.
The study was funded by National Science Foundation.
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Tiny air pollution particles commonly called soot, but also known as black carbon, are in the air and on the move throughout our planet. Black carbon enters the air when fossil fuels and biofuels, such as coal, wood, and diesel are burned. Since black carbon readily absorbs heat from sunlight, the particles can affect Earth’s climate, especially on a regional scale. Though global distribution of soot remains difficult to measure, NASA researchers use satellite data and computer models to better understand how these short-lived particles influence Earth’s climate, cryosphere, and clouds. This scientific data visualization uses data from the GEOS5 GOCART climate model to show black carbon’s atmospheric concentration from August to November in 2009.
Credit: NASA/Goddard Space Flight Center Scientific Visualization Studio
@899
Soot floats on water. Write that down.
Soot constantly settles out of the air onto snow cover.
Fresh snow covers previously settled soot.
When snow melts the soot that was distributed through it stays behind, because it floats, getting darker and darker as the melt progresses.
It is a positive feedback because as it makes the surface darker more insolation is absorbed (you may or may not be aware that dark things get warmer than light things in the sunlight) and that accelerates the melt rate.
If there is not a complete melt with all the snow & ice gone then the soot stays behind on top of the snow that didn’t melt.
Which part of that do you not understand?
re; your diesel w/200,000 miles that has not declined in performance
Wonderful. But unless it’s made of magic metal that doesn’t wear its performance will decline. Cam lobes and tops of intake & exhaust valve stems that ride on them will wear. Compression rings on the piston will wear. Cylinder sleeves will wear. Carbon deposits accumulate in the combustion chamber. All these will eventually result in a decrease in performance. Maybe not noticeable at 200,000 miles as that’s not a lot of miles for a diesel. Get back to me when it has 400,000 miles on it.
@899
P.S. I also have a 3-liter diesel in a John Deere tractor. It’s a 1987 model year with about 1800 hours on it. Unlike my pickup truck the soot coming out the exhaust is dense at times mostly in the lag time between change in throttle setting and change in engine RPM. It has always done that since it was new. Actually it was worse when it was new. The break-in period for diesels is quite a bit longer than for gasoline engines. There is also a great difference in emission standards between commercial diesels (large trucks, busses, agricultural equipment, construction equipment) and light passenger vehicles these days although my truck is still exempt from annual emission testing whereas gasoline passenger vehicles get a probe up the tailpipe in their annual mandatory state inspection. I’d be very interested in how undesireable emissions increase with age. Performance can actually increase as emission control devices become less effective because all emission control schemes rob some engine performance as they do their job. It’s probably safe to say you don’t have a record of annual emission tests for your vehicle.
p.p.s. @899
re; volcano soot
Soot is organic (carbon based) and comes from the incomplete combustion of hydrocarbons.
Volcanoes don’t produce soot. Volcanoes produce ash. Big difference. Volcanic ash is lighter in color and heavier than water as it is composed of very small particles of rock, minerals, and glass.
The only significant natural source of soot is grass, brush, and forest fires. In the natural state (no human fire suppression) fires intense enough to consume living plant matter are rare. Natural decomposers such as insects, fungi, protists, and bacteria quickly make dead plant matter non-combustible after a few years. Natural fires tend to be grass and light brush which aren’t intense enough to ignite forest canopies or even kill larger trees and sweep away any easily combustable materials close to the ground before it can accumulate to the point where it can result in an intense blaze.
Dave Springer says:
August 1, 2010 at 6:48 am
Soot floats on water. Write that down.
Correction: SOME soot floats on water.
Dave Springer says:
August 1, 2010 at 6:48 am
Soot constantly settles out of the air onto snow cover.
And so doesn’t pollen, feathers, dung, etc. Now what?
Dave Springer says:
August 1, 2010 at 6:48 am
Fresh snow covers previously settled soot.
See my remarks above.
Dave Springer says:
August 1, 2010 at 6:48 am
When snow melts the soot that was distributed through it stays behind, because it floats, getting darker and darker as the melt progresses.
No, it doesn’t. Rather, it gets carried away with the melt, just as does pollen, feathers, dung, etc.
You seem inclined to believe that soot magically stays in one place, like a refrigerator magnet …
Dave Springer says:
August 1, 2010 at 6:48 am
It is a positive feedback because as it makes the surface darker more insolation is absorbed (you may or may not be aware that dark things get warmer than light things in the sunlight) and that accelerates the melt rate.
Patronizing, are you?
Dave Springer says:
August 1, 2010 at 6:48 am
If there is not a complete melt with all the snow & ice gone then the soot stays behind on top of the snow that didn’t melt. Which part of that do you not understand?
What part don’t YOU understand about: Just because there’s carbon black on snow and ice, that such won’t go into thermal overload and proceed to dissipate?
If carbon on snow and ice is supposed to be a real problem, then why isn’t all that polar ice and the glaciers melting into oblivion?
Dave Springer says:
August 1, 2010 at 6:48 am
re; your diesel w/200,000 miles that has not declined in performance
Wonderful. But unless it’s made of magic metal that doesn’t wear its performance will decline. Cam lobes and tops of intake & exhaust valve stems that ride on them will wear. Compression rings on the piston will wear. Cylinder sleeves will wear. Carbon deposits accumulate in the combustion chamber. All these will eventually result in a decrease in performance. Maybe not noticeable at 200,000 miles as that’s not a lot of miles for a diesel. Get back to me when it has 400,000 miles on it.
Is that before it’s first overhaul? Or are you possessing of a ‘magical’ engine, as you mention above?
Pre-oilers do wonders for engines. Got one?
899 says:
July 31, 2010 at 1:07 pm
Richard Holle says:
July 30, 2010 at 12:31 pm
I find a thin layer of powered black peat on top of the snow clears the driveway better than salt and with no harmful chemical after effects to the soil.
Well, I dunno, Richard, seeing as how when the temperature here in western Washington, US of A, is below freezing, your idea wouldn’t work nearly as well as a good snow shovel, and it would take far longer.
____________________________Reply;
I have 120 yards of driveway I am 63 I have no intention of using a shovel to clear snow in excess of 10″ in depth, (less than that my 4Wdrive needs no shoveling) a 50# bag of black peat will speed up the removal by a week, with almost no work.
Live in North Central Kansas 3/4 mile off of blacktop.
are the Himalayas the main source of soot in India, or does the soot stop at the Himalayas and cannot cross over into Tibet ? From the video it looks that way.
… and for August and September the direction of the winds seems wrong, shouldn’t it blow from SW to NE ?