monkeyboy
23-07-2009, 11:58 PM
http://blogs.usatoday.com/sciencefair/2009/07/clouds-may-be-thinning-due-to-global-warming.html
Clouds may be thinning due to global warming
Cloudx-large Clouds decline due to global warming, suggests a study of the Northeast Pacific, which in turn would lead to more climate change.
Clouds reflect sunlight, cooling the atmosphere, note the Science study authors led by Amy Clement of the University of Miami. Whether global warming creates more clouds or less "remain a primary cause of uncertainty in global climate model projections," says the study. Global warming is projected to raise average atmospheric temperatures from 3 to 7 degrees Fahrenheit this century, by best estimate of the 2007 International Panel on Climate Change.
Looking at North Pacific cloud records from 1952 to 2007, the study concludes clouds likely thin with warming. Only one climate model includes this added warming effect, they note.
"Unless one has some way to interpret the results in terms of global behavior, it is impossible to infer climate feedbacks from regional observations since motions could simply be redistributing clouds - which, over the globe, could be a zero sum game," cautions Richard Lindzen of MIT, by email. However, Anthony DelGenio of NASA's Goddard Institute for Space Science says studies are now beginning to show that clouds decrease due to warming. "While these don't guarantee that clouds will decrease over the 21st Century, I'd say that the onus is now on those who wish to claim the opposite to provide similarly compelling observational metrics. It has been stated that clouds may either enhance or decrease warming, but the scales are beginning to tilt."
http://blogs.usatoday.com/.a/6a00d83451b46269e20115713517f1970c-350wi
By Dan Vergano
Top photo: The sun shines behind a thunderstorm cloud as it develops near Roswell, N.M. on Sept. 23, 2007. (Mark Wilson, AP/Roswell Daily Record)
Bottom photo: Charts showing increasing temperatures and changing air pressure due to loss of cloud cover in the north Pacific. (University of Miami)
defdog99 (0 friends, send message) wrote: 3h 5m ago
Nova's episode on Global Dimming was quite interesting...
c laird478 (11 friends, send message) wrote: 1h 52m ago
Strong Evidence That Cloud Changes May Exacerbate Global Warming Shown From New Study
ScienceDaily (July 23, 2009)
...
Together, the observations and the Hadley Centre model results provide evidence that low-level stratiform clouds, which currently shield the earth from the sun's radiation, may dissipate in warming climates, allowing the oceans to further heat up, which would then cause more cloud dissipation.
"This is somewhat of a vicious cycle potentially exacerbating global warming," said Clement.
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I wonder if netdr would consider this an example of positive feedback.
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so thats what barium and aluminium particals in the atmosphere do. :rolleyes:
Clouds may be thinning due to global warming
Cloudx-large Clouds decline due to global warming, suggests a study of the Northeast Pacific, which in turn would lead to more climate change.
Clouds reflect sunlight, cooling the atmosphere, note the Science study authors led by Amy Clement of the University of Miami. Whether global warming creates more clouds or less "remain a primary cause of uncertainty in global climate model projections," says the study. Global warming is projected to raise average atmospheric temperatures from 3 to 7 degrees Fahrenheit this century, by best estimate of the 2007 International Panel on Climate Change.
Looking at North Pacific cloud records from 1952 to 2007, the study concludes clouds likely thin with warming. Only one climate model includes this added warming effect, they note.
"Unless one has some way to interpret the results in terms of global behavior, it is impossible to infer climate feedbacks from regional observations since motions could simply be redistributing clouds - which, over the globe, could be a zero sum game," cautions Richard Lindzen of MIT, by email. However, Anthony DelGenio of NASA's Goddard Institute for Space Science says studies are now beginning to show that clouds decrease due to warming. "While these don't guarantee that clouds will decrease over the 21st Century, I'd say that the onus is now on those who wish to claim the opposite to provide similarly compelling observational metrics. It has been stated that clouds may either enhance or decrease warming, but the scales are beginning to tilt."
http://blogs.usatoday.com/.a/6a00d83451b46269e20115713517f1970c-350wi
By Dan Vergano
Top photo: The sun shines behind a thunderstorm cloud as it develops near Roswell, N.M. on Sept. 23, 2007. (Mark Wilson, AP/Roswell Daily Record)
Bottom photo: Charts showing increasing temperatures and changing air pressure due to loss of cloud cover in the north Pacific. (University of Miami)
defdog99 (0 friends, send message) wrote: 3h 5m ago
Nova's episode on Global Dimming was quite interesting...
c laird478 (11 friends, send message) wrote: 1h 52m ago
Strong Evidence That Cloud Changes May Exacerbate Global Warming Shown From New Study
ScienceDaily (July 23, 2009)
...
Together, the observations and the Hadley Centre model results provide evidence that low-level stratiform clouds, which currently shield the earth from the sun's radiation, may dissipate in warming climates, allowing the oceans to further heat up, which would then cause more cloud dissipation.
"This is somewhat of a vicious cycle potentially exacerbating global warming," said Clement.
---
I wonder if netdr would consider this an example of positive feedback.
------------------------------------------
so thats what barium and aluminium particals in the atmosphere do. :rolleyes: