On the other hand there are numerous positive feedbacks. Particularly that higher temperatures increase the amount of water vapour in the air (7% per 1 deg C) which is again a stronger GHG than CO2. Loss of ice cover over the sea changes the surface from reflecting 90% of the radiation to absorbing in excess of 80%.
Higher temperatures of themselves also increase the amount of carbon based GHGs in the atmosphere EG forest fires, increased methane emission's from tundra and peat areas
None of these positive feedbacks have actually been proven or observed, actually. If the net atmospheric feedbacks are negative, then the positive snow-albedo feedback would not be quite as great. With sea ice declines over the Arctic, you get more cloud cover, resulting in a negative feedback over the Arctic.
Yes they have. The recent fires in Colorado did not add more CO2 to the atmosphere ? heating water does not produce evaporation ? melting permafrost does not release methane to the atmosphere.http://www.youtube.com/watch?v=YegdEOSQotE&feature=player_detailpage
It has been observed that the climate system emits more OLR at a rate that is greater than a black body and is greater than the climate models, suggesting negative cloud feedback and neutral water vapor feedback.
No the opposite is true if we were to take take the earth as a simple black body the temperature would be some 30 deg C cooler than is observed.
The models had the greatest warming at 200-300 hPa, which is associated with a negative lapse rate feedback, as the upper troposphere in the models is warming faster than the surface.Once again, according to observations, we can see that there is a serious discrepency between the models and the observations at various locations in the upper troposphere.
You are I think are referring to the what is called the tropical hot spot which has been discussed at great length but in reality is has nothing to do with the green house effect it is simply a predicted consequence of higher global temperatures regardless of the cause.
If you think that Climate4you.com is cherry picking by selecting the HatAT dataset, look at Douglass et. al 2007, which has 3 MORE datasets that show that there is a serious discrepency between modeled and observational temperatures in the Tropical Troposphere.
The data is a problem here as much of it was based on balloon data which is know to have some fairly serious errors in it.
The figure, from Douglass et. al 2007 shows that the models were predicting a negative lapse rate feedback, which is seen with the higher temperature trend in the middle to upper troposphere than at the surface. Observations do not show any of this. They show that the lapse rate is positive, and that the surface is warming faster than the upper troposphere, consistent with a positive lapse rate feedback. The strongest negative lapse rate feedbacks in the IPCC GCMs were constantly associated with a the strongest positive water vapor feedbacks. The relationship between the two appears to be robust, so the lack of a negative lapse rate indicates that the water vapor feedback might not be positive, and even negative.
That is very confused. Lets keep it simple the rate at which temperature falls with height is expected to not be as quick, due to GHGs as it where holding on to the heat. This in turn means that the atmosphere is warmer at height where it is easier for the heat to escape to space rather than being reflected to the surface. This is in fact an example of a negative feedback due GHGs but if you accept that it is indeed true then you also have to accept the rest of the predictions in relation to near surface warming.
Or the fact that humidity levels are remaining constant as temperatures increase, as seen with Wang et. al 2008
Please clarify whether you mean relative or specific humidity it makes a huge difference.