Cirrus disappearance: Warming might thin heat-trapping clouds (8/9/2007)
"The widely accepted (albeit unproven) theory that manmade global warming will accelerate itself by creating more heat-trapping clouds is challenged this month in new research from The University of Alabama in Huntsville.
Instead of creating more clouds, individual tropical warming cycles that served as proxies for global warming saw a decrease in the coverage of heat-trapping cirrus clouds, says Dr. Roy Spencer, a principal research scientist in UAHuntsville's Earth System Science Center.
That was not what he expected to find.
"All leading climate models forecast that as the atmosphere warms there should be an increase in high altitude cirrus clouds, which would amplify any warming caused by manmade greenhouse gases," he said. "That amplification is a positive feedback. What we found in month-to-month fluctuations of the tropical climate system was a strongly negative feedback. As the tropical atmosphere warms, cirrus clouds decrease. That allows more infrared heat to escape from the atmosphere to outer space."
The results of this research were published today in the American Geophysical Union's "Geophysical Research Letters" on-line edition. The paper was co-authored by UAHuntsville's Dr. John R. Christy and Dr. W. Danny Braswell, and Dr. Justin Hnilo of Lawrence Livermore National Laboratory, Livermore, CA."
Read it all at the UAH site.
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I'll have to take this with a grain of salt. I haven't seen any climatology hypotheses that state that cirrus clouds will only result in more global warming. On the contrary, more clouds would, in turn, bounce infrared energy back up into space, thereby cooling the earth as well as warming it.
ReplyDeleteWhile more cirrus clouds are predicted by current models, they depend on a significant warming of the oceans, which--for whatever reason--has not happened. They have warmed though, just not at the rate of the atmosphere. You might expect as much, and most do: it's physics.
Again, I think that taking conclusions from data sets such as these is as foolish as making conclusions based on the other sides' sets.
I will say, in the pro-climate change's defense, the earth is getting warmer (than it was 700 years ago), and atmospheric CO2 is rising sharply. It's now their job to connect the one to the other, instead of just correlating them. However, I will not rely on straw-man arguments about clouds to make my decision. Sorry, but I'm just a mean-old asshole with too much science education.