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Post by steve on Oct 20, 2010 14:01:27 GMT
You are being incoherent again. Feedback from water vapour is being compared with the temperature change not the level of CO2. That is what Dessler's study is about. Steve throws in a little anecdotal astrometeorology here. . . .the amateur variety. Half an analysis is an analysis for half wits. Suitable for you then?
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Post by randwick on Oct 20, 2010 16:23:03 GMT
. You guys seems to think in radiative terms , anything with water , a change in thermal balance is the first effect
The hydrological system is the biggest climate modifier there is except night , it can cool at a continent size by rain evaporation
If surface temperature increase , global moisture increase the cycle increase cloud cover and radiate latent heat , ........perfect !
what is astonishing is how self regulating the atmosphere has been in the geological past .
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Post by steve on Oct 20, 2010 16:35:02 GMT
. You guys seems to think in radiative terms , anything with water , a change in thermal balance is the first effect The hydrological system is the biggest climate modifier there is except night , it can cool at a continent size by rain evaporation If surface temperature increase , global moisture increase the cycle increase cloud cover and radiate latent heat , ........perfect ! what is astonishing is how self regulating the atmosphere has been in the geological past . Well I personally don't like to think just in "radiative terms", even if some on the board claim that I and others do. The assumption that increased temperature followed by increased humidity leads to increased clouds does not automatically follow. A lot of studies indicate that *relative* humidity decreases which one *might* assume means less cloud. Also, some clouds keep the planet warm by keeping in heat and let in sunlight. Some cool it by reflecting sunlight. The location of cloud is important too - a cumulous cloud in the tropics might have a bigger radiative effect than a swath of stratus near the poles. The atmosphere is indeed nicely regulated, but not so much that it stops quite significant changes in climate to apparently small effects.
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Post by hunterson on Oct 20, 2010 20:52:25 GMT
"The atmosphere is indeed nicely regulated, but not so much that it stops quite significant changes in climate to apparently small effects. " A great truth, if only it were true.
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Post by socold on Oct 20, 2010 20:54:41 GMT
Also the height of clouds is important. If the average height increases then that has a warming effect, a decrease has a cooling effect.
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Post by northsphinx on Oct 21, 2010 5:55:02 GMT
Also the height of clouds is important. If the average height increases then that has a warming effect, a decrease has a cooling effect. That is right. But that also include top of water vapor which is GHG that is not well mixed in atmosphere. Water vapor will act as a cloud up to where it dry out. But an invisible to eye. And CO2. But here is the thing that top of the CO2 "cloud" are the tropopause height. Add more CO2 and that will rise the working top of CO2 cloud even further. In areas where temperature rise with height.
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Post by hunterson on Oct 21, 2010 9:29:12 GMT
Also the height of clouds is important. If the average height increases then that has a warming effect, a decrease has a cooling effect. Are you talking about the altitude at which the cloud forms, or the height of the cloud?
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Post by hunterson on Oct 21, 2010 9:30:00 GMT
Steve throws in a little anecdotal astrometeorology here. . . .the amateur variety. Half an analysis is an analysis for half wits. Suitable for you then? Not at all. Just what we expect from AGW believers.
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Post by nautonnier on Oct 22, 2010 1:12:40 GMT
Also the height of clouds is important. If the average height increases then that has a warming effect, a decrease has a cooling effect. Give a cite for your claim SoCold observational not models.
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Post by icefisher on Oct 22, 2010 2:10:55 GMT
Not at all. Just what we expect from AGW believers. One only has to look who started the thread with half an analysis.
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Post by socold on Oct 23, 2010 1:33:02 GMT
Also the height of clouds is important. If the average height increases then that has a warming effect, a decrease has a cooling effect. Give a cite for your claim SoCold observational not models. Can't without looking for it again I am afraid, it's something I read which I have repeated. Here's some relevant links. These aren't where I read it but they do mention it in passing: www.giss.nasa.gov/research/briefs/delgenio_03/earthobservatory.nasa.gov/IOTD/view.php?id=44250
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Post by icefisher on Oct 23, 2010 3:42:20 GMT
These aren't where I read it but they do mention it in passing: I think you just described pseudoscience.
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Post by socold on Oct 23, 2010 3:49:55 GMT
yes you have a point. Learning things is psuedoscience.
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Post by nautonnier on Oct 23, 2010 18:07:00 GMT
First reference started well - but then spoilt it by: "What does this mean for climate change? Mao-Sung Yao, Tselioudis, Del Genio, and William Kovari used the GISS global climate model to predict changes in different types of clouds, and the sensitivity of the climate, to a doubling of carbon dioxide concentration. They found that low-level clouds in the model behaved much the same as anticipated from satellite and surface data. At midlatitudes, clouds became a bit thinner and less reflective in the simulated warmer climate" So the actual effect was assumed then modeled the references I gave to glc actually measured the forcing of the clouds directly Your second paper measures 'thermal energy' from clouds i.e. OLR not the albedo and actually goes on to say: "Clouds impact temperatures in other ways as well. They also reflect energy, shading and cooling the Earth. On balance, scientists aren’t entirely sure what effect clouds will have on global warming. Most climate models predict that clouds will amplify global warming slightly. Some observations of clouds support model predictions, but direct observational evidence is still limited. Clouds remain the biggest source of uncertainty (apart from human decisions to control greenhouse gas emissions) in predicting how much global temperatures will change"Both articles are 10 years old and the latest observations from ERBE and other recent satellites supports the strong negative forcing over high SSTs for example.
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Post by socold on Oct 23, 2010 18:21:14 GMT
"So the actual effect was assumed then modeled the references I gave to glc actually measured the forcing of the clouds directly"
The forcing is expected to be negative. The issue isn't what the sign of the forcing current is now, it's how that will change in a warmer world. Of course you can't measure that without a time machine. Therefore you have to calculate it based on theory (ie models).
The key part from the links though is support for my claim that high level clouds have a warming effect on Earth while low level clouds have a cooling effect:
"Clouds both reflect sunlight, which cools the Earth, and trap heat in the same way as greenhouse gases, thus warming the Earth. Different types of clouds do more of one than the other. The net effect of clouds on climate change depends on which cloud types change, and whether they become more or less abundant, thicker or thinner, and higher or lower in altitude."
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