Is there an inconsistency in the argument for CO2 being the controlling GHG (often called the CO2 "control knob" effect)?

In anthropogenic global warming theory, CO2 is regarded as the controlling GHG despite the fact that H2O vapor is by far the strongest GHG, both spectrally and in concentration. AGW advocates argue this point by claiming that the H20 vapor greenhouse effect cannot be a temperature "forcing" due to its... show more In anthropogenic global warming theory, CO2 is regarded as the controlling GHG despite the fact that H2O vapor is by far the strongest GHG, both spectrally and in concentration. AGW advocates argue this point by claiming that the H20 vapor greenhouse effect cannot be a temperature "forcing" due to its short molecular "residence time" resulting from the fact that H2O vapor is condensible over the temperature and pressure ranges on earth. Therefore the amount of water vapor available for driving the H2O greenhouse effect is near zero when considering this effect as a temperature forcing.

When regarding the H2O vapor concentration as a temperature "feedback" to the CO2 greenhouse effect, however, the H2O vapor concentration is taken as the value given by the Clausius-Claperyon equation for the current temperature. In this manner, it is argued that it is the CO2 greenhouse effect that sets the temperature while the much stronger H2O greenhouse effect merely responds to it, acting as an amplifier.

Now there can only be one value of the H2O vapor concentration at any given time. So which is it!?

It is essential that this matter be resolved or there is no scientific basis for AGW, and we need to look to other sources for explanations of any global warming that may be occurring.
Update: I should note that I asked this same question about a week ago, and got some good helpful answers. Unfortunately, however, I also got a bunch of comments that were in clear violation of the Yahoo posting guidelines for being insulting and totally irrelevant chatter. I personally reported these violations hoping... show more I should note that I asked this same question about a week ago, and got some good helpful answers. Unfortunately, however, I also got a bunch of comments that were in clear violation of the Yahoo posting guidelines for being insulting and totally irrelevant chatter. I personally reported these violations hoping that the offending comments would simply be removed, but instead the entire question and all of the good responses were also removed. My apologies to those who tried to be helpful, ...
Update 2: but their inputs were simply lost. I will not repeat the mistake of reporting violations of Yahoo guidelines in postings responding to my own questions.
Update 3: After examining the answers and comments this question has received, I believe that the problem with the analysis leading to the CO2 control knob effect and the "fact" that water vapor cannot be a forcing comes from misapplication of thermal equilibrium-based "laboratory physics" (including the... show more After examining the answers and comments this question has received, I believe that the problem with the analysis leading to the CO2 control knob effect and the "fact" that water vapor cannot be a forcing comes from misapplication of thermal equilibrium-based "laboratory physics" (including the Clausius-Claperyon equation) to an atmosphere that is far from equilibrium. It is not an inconsistency within the theory itself as I originally thought.
Update 4: By assuming a water vapor concentration that is rigidly constrained in real time to the value predicted by the Clausius-Claperyon equation, any "extra" water vapor above this concentration would instantaneously condense, thereby preventing a water vapor temperature forcing. With a more accurate dynamical... show more By assuming a water vapor concentration that is rigidly constrained in real time to the value predicted by the Clausius-Claperyon equation, any "extra" water vapor above this concentration would instantaneously condense, thereby preventing a water vapor temperature forcing. With a more accurate dynamical model not constrained to thermal equilibrium, however, such a forcing would be possible since the "extra" water vapor still causes greenhouse warming until it actually does condense.
Update 5: This extra greenhouse warming also causes a temperature increase. Therefore, we have a situation where an increase in water vapor CAUSED (not just responded to) a temperature change. Hence, water vapor can be a forcing under this model. But no such model is ever referenced in the arguments presented by the AGW... show more This extra greenhouse warming also causes a temperature increase. Therefore, we have a situation where an increase in water vapor CAUSED (not just responded to) a temperature change. Hence, water vapor can be a forcing under this model. But no such model is ever referenced in the arguments presented by the AGW advocates. Instead, they go strictly by the "laboratory physics" which prevents water vapor forcings.
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