From Lawrence Berkeley National Labs, and announcement that comes at a very inconvenient time for IPCC and Pachauri while their “Glaciergate” issue rages. Aerosols and black carbon are tagged as the major drivers. And no mention of disappearance by 2035.
Black Carbon a Significant Factor in Melting of Himalayan Glaciers
The fact that glaciers in the Himalayan mountains are thinning is not disputed. However, few researchers have attempted to rigorously examine and quantify the causes. Lawrence Berkeley National Laboratory scientist Surabi Menon set out to isolate the impacts of the most commonly blamed culprit—greenhouse gases, such as carbon dioxide—from other particles in the air that may be causing the melting. Menon and her collaborators found that airborne black carbon aerosols, or soot, from India is a major contributor to the decline in snow and ice cover on the glaciers.
“Our simulations showed greenhouse gases alone are not nearly enough to be responsible for the snow melt,” says Menon, a physicist and staff scientist in Berkeley Lab’s Environmental Energy Technologies Division. “Most of the change in snow and ice cover—about 90 percent—is from aerosols. Black carbon alone contributes at least 30 percent of this sum.”
Menon and her collaborators used two sets of aerosol inventories by Indian researchers to run their simulations; their results were published online in the journal Atmospheric Chemistry and Physics.
The actual contribution of black carbon, emitted largely as a result of burning fossil fuels and biomass, may be even higher than 30 percent because the inventories report less black carbon than what has been measured by observations at several stations in India. (However, these observations are too incomplete to be used in climate models.) “We may be underestimating the amount of black carbon by as much as a factor of four,” she says.
The findings are significant because they point to a simple way to make a swift impact on the snow melt. “Carbon dioxide stays in the atmosphere for 100 years, but black carbon doesn’t stay in the atmosphere for more than a few weeks, so the effects of controlling black carbon are much faster,” Menon says. “If you control black carbon now, you’re going to see an immediate effect.”
The Himalayan glaciers are often referred to as the third polar ice cap because of the large amount of ice mass they hold. The glacial melt feeds rivers in China and throughout the Indian subcontinent and provide fresh water to more than one billion people.
Atmospheric aerosols are tiny particles containing nitrates, sulfates, carbon and other matter, and can influence the climate. Unlike other aerosols, black carbon absorbs sunlight, similar to greenhouse gases. But unlike greenhouse gases, black carbon does not heat up the surface; it warms only the atmosphere.
This warming is one of two ways in which black carbon melts snow and ice. The second effect results from the deposition of the black carbon on a white surface, which produces an albedo effect that accelerates melting. Put another way, dirty snow absorbs far more sunlight—and gets warmer faster—than pure white snow.
Previous studies have shown that black carbon can have a powerful effect on local atmospheric temperature. “Black carbon can be very strong,” Menon says. “A small amount of black carbon tends to be more potent than the same mass of sulfate or other aerosols.”
Black carbon, which is caused by incomplete combustion, is especially prevalent in India and China; satellite images clearly show that its levels there have climbed dramatically in the last few decades. The main reason for the increase is the accelerated economic activity in India and China over the last 20 years; top sources of black carbon include shipping, vehicle emissions, coal burning and inefficient stoves. According to Menon’s data, black carbon emitted in India increased by 46 percent from 1990 to 2000 and by another 51 percent from 2000 to 2010.
This map of the change in annual linear snow cover from 1990 to 2001 shows a thick band (blue) across the Himalayas with decreases of at least 16 percent while a few smaller patches (red) saw increases. The data was collected by the National Snow and Ice Data Center.
However, black carbon’s effect on snow is not linear. Menon’s simulations show that snow and ice cover over the Himalayas declined an average of about one percent from 1990 to 2000 due to aerosols that originated from India. Her study did not include particles that may have originated from China, also known to be a large source of black carbon. (See “Black soot and the survival of the Tibetan glaciers,” by James Hansen, et al., published last year in the Proceedings of the National Academy of Sciences.) Also the figure is an average for the entire region, which saw increases and decreases in snow cover. As seen in the figure, while a large swath of the Himalayas saw snow cover decrease by at least 16 percent over this period, as reported by the National Snow and Ice Data Center, a few smaller patches saw increases.
Menon’s study also found that black carbon affects precipitation and is a major factor in triggering extreme weather in eastern India and Bangladesh, where cyclones, hurricanes and flooding are common. It also contributes to the decrease in rainfall over central India. Because black carbon heats the atmosphere, it changes the local heating profile, which increases convection, one of the primary causes of precipitation. While this results in more intense rainfall in some regions, it leads to less in other regions. The pattern is very similar to a study Menon led in 2002, which found that black carbon led to droughts in northern China and extreme floods in southern China.
“The black carbon from India is contributing to the melting of the glaciers, it’s contributing to extreme precipitation, and if black carbon can be controlled more easily than greenhouse gases like CO2, then it makes sense for India to regulate black carbon emissions,” says Menon.
Berkeley Lab is a U.S. Department of Energy national laboratory located in Berkeley, California. It conducts unclassified scientific research for DOE’s Office of Science and is managed by the University of California. Visit our Website at www.lbl.gov/
Additional information:
- Read the paper, “Black carbon aerosols and the third polar ice cap”
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Ref – Anticlimactic (20:34:37) :
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You’re right.
The older I get the more frustrated I become with the limitations of my “language” abilities, and the apparent limitations of what I perceive as everyone elses as well. I usually blame the language (in this case American English) and not myself or anyone else. When I really get mad, I blame the teacher’s union(s) and our current system of education. When my Irish gets really, really boiling mad, I blame God.
Many times I feel we’ve definitely lost something on our way to the 21st Century. I haven’t been able to put my finger on it. Maybe it’s like the weather, just to much to comprehend.
Sometimes I also think we haven’t lost anything at all, that life’s a beach, always the same and always different.
As you corrected me: “God save us from self-righteous men!”
Phil. (22:01:15) :
The text seems to switch between talking about snow melt and glacier melt, so which is it Richard?
Well, you need to take that up with LBNL. I thought they transitioned quite well and only discussed glaciers as also being impacted, but not part of the study.
If you actually read the article you’ll see they make no mention of the 2035 date as AW points out. You’re the only one claiming the 2035 date might be valid based on snow cover melt. Maybe a reading comprehension course is in your future?
J.Peden said;
“If people are tolerating smoke filled rooms – doubtful, because it’s not that hard to avoid, unless they’re not as smart as American Indians – they should more likely be getting CO poisoning. It competes with O2 at a rate of about 220/1, so all that’s needed is a CO concentration of about 0.1% vs O2’s 20% to get half of one’s hemoglobin occupied by CO, which is ususally a deadly effect.”
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I remember marvelling, when I was in India in the seventies, how such an old culture had failed to come up with the concept of a chimney. Although the smoke in the unglazed houses was not usually dense and suffocating, I recall having to go outside to escape stinging eyes.
It’s interesting that the northern North American Indians understood the chimney, but didn’t figure out pottery or metals.
It’s akin to a certain more modern group that can discern variations of a mm in the surface of the sea, but can’t find the heat pipeline.
Oliver Ramsay (07:39:38) :
I remember marvelling, when I was in India in the seventies, how such an old culture had failed to come up with the concept of a chimney. Although the smoke in the unglazed houses was not usually dense and suffocating, I recall having to go outside to escape stinging eyes.
Interesting! And so maybe the in house smoke does something good? Or not. Regardless, that combination of possibly increased hemoglobin CO levels plus airway irritation would probably be harder on children. I hope the relevant authorities have not themselves been too “overcome” by AGW to deal with such issues.
George E. Smith:
The “Residence” time of a single CO2 molecule in the atmosphere, is as critical to life on earth as the mean lifetime of a single Krill crustacean in the earth’s oceans; namely, not at all;
Yes, I took that “residence time” of CO2 argument to be propagandistic or wishful nonsense almost immediately, when compared to the way water vapor works, often as a very short lifespanned entity but in essentially infinite instantaneous supply – it seemed so obvious that I wondered what I was missing for a little while. Who cares how long they each live compared to how many of them there are in the atmosphere and what they do there? For one thing, I guess the little man made CO2’s from evil ‘fossil fuel’ were supposed to be ipso facto especially pernicious?
NASA have come to similar findings about soot and the Himalayan glaciers published back in December, 2009.
http://www.nasa.gov/topics/earth/features/himalayan-soot.html
http://www.nasa.gov/topics/earth/features/himalayan-warming.html
NASA have come to similar findings about soot and the Himalayan glaciers published back in December, 2009.
http://www.nasa.gov/topics/earth/features/himalayan-soot.html
http://www.nasa.gov/topics/earth/features/himalayan-warming.html
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Correction on date of last post: 2009 not 2010
About tax on soot…..
In Norway, the tax on diesel was very low for many years…
More and more diesel-cars appeared on the scene……now the tax-level for diesels are close to the petrol-tax….. same with so called bio-diesel…. so….the goal is in the end…. more tax.
Everywhere. Not to save the environment.
The Government-bureacrazy is groving every year.
There is no limit.
Someone must pay for it.
And thats us.
J.Peden (09:36:24) :
Oliver Ramsay (07:39:38) :
“I remember marvelling, when I was in India in the seventies, how such an old culture had failed to come up with the concept of a chimney. Although the smoke in the unglazed houses was not usually dense and suffocating, I recall having to go outside to escape stinging eyes.”
Interesting! And so maybe the in house smoke does something good? Or not. Regardless, that combination of possibly increased hemoglobin CO levels plus airway irritation would probably be harder on children. I hope the relevant authorities have not themselves been too “overcome” by AGW to deal with such issues.
Henan province in China has the highest incidence of oesophageal cancer in the world, widely attributed to smoke from the traditional stoves. A research project I was involved in found many mutagenic compounds present in the soot from those stoves.