Back in March Climateaudit published this blog. This deals with the suppression of a paper that says there is no evidence for a rise in the level of water vapour in the upper atmosphere in the recent past. Why is this important? The forecasts of dramatic rise in global temperatures are based upon the small rise in global temperatures so far experienced (and claimed to be caused by increases in greenhouse gases) resulting in higher levels of water vapour in the middle and upper troposphere. Without this positive feedback loop, the current 2oC to 4oC rise in temperatures predicted for this century are dramatically reduced.
The bottom line is that, if (repeat if) one could believe the NCEP data ‘as is’, water vapour feedback over the last 35 years has been negative. And if the pattern were to continue into the future, one would expect water vapour feedback in the climate system to halve rather than double the temperature rise due to increasing CO2.
In other words, if the data is right, expect global temperatures to rise by 0.5 oC.
The response should be one of ‘let us pursue this further’, not ‘let us squash this, as it rocks the boat’.
ManicBeancounter 
EdBhoy
/ 26/05/2009The issue of feedback is absolutely crucial to the 20 or so climate models that are used to predict the coming global warming Armageddon. They all assume various degrees of positive feedback from water vapor, so they all predict large increases in global temperatures. Inputting a negative feedback to the models will bring their predictions in line with recent observed temperatures but the intense political pressure to maximise the future extent of global warming prevents them from considering the empirical evidence that the feedback may be negative.