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Brown clouds boost global warming - Aerosols over Asia incriminated in Himalayan glacial melting.
news@nature.com ^
| 1 August 2007
| Daniel Cressey
Posted on 08/01/2007 9:19:43 PM PDT by neverdem
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Published online: 1 August 2007; | doi:10.1038/news070730-6 Brown clouds boost global warmingAerosols over Asia incriminated in Himalayan glacial melting.Daniel Cressey
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Clouds of pollution sit over southern Asia for half the year. NASA/GODDARD SPACE FLIGHT CENTER/J. SCHMALTZ |
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Tiny particles of pollution may be causing as much warming as greenhouse gases over southern Asia. The clouds of aerosol particles are contributing to the potentially devastating melting of Himalayan glaciers, say researchers.
Using data from unmanned aircraft flying through 'brown clouds' of aerosol pollution over the Indian Ocean, US researchers found the zone of the atmosphere containing the clouds is warming by 0.25 ºC, compared with 0.10 ºC per decade at ground level.
The Himalayas and the clouds occupy the same zone of the atmosphere, so the extra warming could be accelerating glacial retreat.
"This is a big topic of conversation over there [in India]. Much of the water supply of north and central India is from major rivers fed by glaciers in the Himalayas," says study author David Winker of the NASA Langley Research Center in Virginia.
Temperatures rising
On a global scale, clouds of aerosols from biomass burning and fossil fuel consumption cool the atmosphere by reflecting sunlight back into space. But the particles also absorb solar radiation, and it has been suspected they could warm certain levels of the atmosphere.
"It is becoming more obvious that the role of aerosols is not as simple as we once thought," says Piers Forster, an Earth scientist at the University of Leeds, UK. "They don't just provide cooling, they're actually giving far more complicated and regional changes."
Direct measurements of the effects of aerosols are difficult, and satellite measurements have been available for only five years. To investigate the question, in March 2006 Winker and his colleagues flew 18 unmanned aircraft missions from the small island of Hanimaadhoo in the Maldives. They report their results in Nature1.
Three aircraft flew over the Indian Ocean simultaneously at between 0.5 and 3 kilometres above sea level. In the second half of the month — when there was heavy pollution arriving from southern Asia — the heating rate of this band of the atmosphere more than doubled.
Occurring annually, Asian brown clouds can cover parts of southern Asia, as well as the Arabian Sea and the Bay of Bengal, from November to April2.
Melting ice
Using simulations of atmospheric heating from 1950 to the present, the team determined that brown clouds plus greenhouse gases contributed 0.15 ºC to the warming trend of 0.25 ºC per decade in this part of the atmosphere.
"The data show the brown-cloud heating is as much as 50% of the background heating of the atmosphere," says the study's leader, climatologist Veerabhadran Ramanathan of the Scripps Institution of Oceanography in San Diego, California.
The simulation results are similar to observations, he adds. "Glaciologists have shown the Himalayan region has been warming by a quarter of a degree per decade. That is almost twice the warming trend of the global warming."
"[Aerosols] are very important on the regional scale," says meteorologist Eleanor Highwood of the University of Reading. Using these aircraft to take direct measurements is a step forward, she adds: "I'd love one."
Visit our newsblog to read and post comments about this story.
References
- Ramanathan, V. et al. Nature 448, 575-578 (2007). | Article |
- Ramanathan, V. et al. Curr. Sci. 83, 947-955 (2002).
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TOPICS: Culture/Society; Extended News; News/Current Events
KEYWORDS: aerosols; agw; brownclouds; climatechange; globalwarming; science
1
posted on
08/01/2007 9:19:48 PM PDT
by
neverdem
To: xcamel; DaveLoneRanger
2
posted on
08/01/2007 9:22:29 PM PDT
by
neverdem
(Call talk radio. We need a Constitutional Amendment for Congressional term limits. Let's Roll!)
To: neverdem
Who is making these new brown clouds?
Who is making these clouds so brown?
Who is making these new brown clouds?
Better go ask a philostopher.
3
posted on
08/01/2007 9:23:24 PM PDT
by
MistrX
To: MistrX
people.
but...not the people the enviros want to blame
4
posted on
08/01/2007 9:31:52 PM PDT
by
ari-freedom
(Never attribute to malice that which is adequately explained by stupidity.)
To: MistrX
5
posted on
08/01/2007 9:44:37 PM PDT
by
knarf
(I say things that are true ... I have no proof ... but they're true.)
To: MistrX
Al Gore’s pontifications from his ass.
6
posted on
08/01/2007 9:46:51 PM PDT
by
beethovenfan
(If Islam is the solution, the "problem" must be freedom.)
To: beethovenfan
No ... that would be bullshit farts
7
posted on
08/01/2007 9:53:09 PM PDT
by
knarf
(I say things that are true ... I have no proof ... but they're true.)
To: neverdem
Basic References:
Lawrence Solomon's "The Deniers" (a series of articles on the view of scientists who have been labelled "Global Warming Deniers"):
Other References:
8
posted on
08/01/2007 10:02:51 PM PDT
by
sourcery
(fRed Dawn: Wednesday, 5 November 2008!)
To: neverdem
AlGores inconvenient Brown Clouds...
To: AngelesCrestHighway
I was listening to Fox’s coverage of the bridge collapse, when they had Greta Wilson (I think that is her name) who made the comment that is has been unusually hot in MN this summer and maybe that caused it. So Fox has the scoop “Global warming causes I-35 collapse”. Fair and balanced reporting at its finest.
10
posted on
08/01/2007 10:33:13 PM PDT
by
MPJackal
("If you are not with us, you are against us.")
To: MPJackal
“unusually hot in MN this summer “
Is that even true?
Yesterday, I heard reports that weather in most of the US had been unusually cool this summer.
11
posted on
08/02/2007 1:37:39 AM PDT
by
AlexW
(Reporting from Bratislava, Slovakia. Happy not to be back in the USA for now.)
To: AlexW
Only TX has been cooler than normal. Southern ID was in the 112s(F) a month ago.
12
posted on
08/02/2007 3:58:16 AM PDT
by
rahbert
To: neverdem
I thought the himmmylaian (sp) glaciers were growing.
13
posted on
08/02/2007 6:37:11 AM PDT
by
traviskicks
(http://www.neoperspectives.com/Ron_Paul_2008.htm)
To: neverdem
When the earth was cooling between 1945-1976 they claimed it was because sulfate aerosols were masking global warming. Now they are saying that these very same aerosols are now heating the earth.
Whatever fits I guess
14
posted on
08/02/2007 9:21:39 AM PDT
by
qam1
(There's been a huge party. All plates and the bottles are empty, all that's left is the bill to pay)
To: MPJackal
<<
I was listening to Foxs coverage of the bridge collapse, when they had Greta Wilson (I think that is her name) who made the comment that is has been unusually hot in MN this summer and maybe that caused it.
>>
Man, that’s Nancy Grace - Cameron Diaz - Elton John class of stupid. Way to go, Greta. You are now officially amongst the dumbest people on earth.
15
posted on
08/02/2007 2:56:39 PM PDT
by
noblejones
(Ben Stein for President, 2008.)
To: neverdem
Does this mean the planet is doomed even sooner than the libs have been saying??? Brown clouds over Asia. Gotta be Bush`s fault.
To: AlexW
“Is that even true?”
I have no idea. She was on the phone for the interview/report since she is from there. She said something about it being in the 90’s and she doesn’t know if that help cause the collapse, but....
17
posted on
08/02/2007 4:48:24 PM PDT
by
MPJackal
("If you are not with us, you are against us.")
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