Originally Posted by: PeterMG 
At one point I admired this mans tenacity and intellect. But he seems incapable of moving on. He is still harping on that the green house effect is real and CO2 causes warming but that the numbers are wrong and the effect is negligible.
To my mind, and it has to be born in mind I'm just a mere mechanical engineer, the debate has moved on to question the very existence of the greenhouse effect. Nowhere has any proof been produced that demonstrates the greenhouse effect is real. Given this fact I would have though there is a rather large hole in the warmest argument.
But as has been pointed out by Richard over many posts it not about science.
Science is about precision, but politics is bedeviled by ambiguity.
It is true that, in a lab experiment, you can show that CO2 molecules let visible light and UV through, so that they impinge on a solid target behind. This target then heats up and emits IR. The CO2 absorbs the IR radiation and re-emits it in all directions, including back towards the target, which warms up slightly more in consequence. This is the 'greenhouse' effect.
Denying that that happens in the lab is foolish, because it can be shown by experiment. So if Monckton were to 'deny' that the effect exists, he could be swept aside easily politically. The political argument has been:
Does the greenhouse effect exist? - Yes
Then we're all doomed! - No, because the maths and experiment show it to be insignificant.
I'm a politician - I can't do maths. We're all doomed.....
I have, in fact, had almost precisely this response from my local Liberal councillor.
What happens in the real-world atmosphere, however, is a different question again. You are correct to state that the estimated numbers have no experimental justification, and that the models which rely on this effect are probably wrong. In particular, the theory states that the middle troposphere should show a 'hot spot' from this re-radiation, and nothing has ever been found. So the 'greenhouse effect' which can be shown in a lab is either completely nonoperational for some reason in real life, or produces such a minor effect that it is swamped by natural heat exchanges.
Myself, I believe that the effect might provide a very small heat increase at the surface if the atmosphere could be held static. But that in fact, the atmosphere undergoes huge bouts of convective activity, during which masses of heat is carried into the stratosphere by phenomena like thunderstorms - and it is these heat exchanges which determine the actual temperature of the land surface. Furthermore, the processes are inherently stable, so that if excess heat occurs then more convection occurs to dispel it. Under these circumstances it makes a lot of sense to say that, for an engineer dealing in tolerances, the greenhouse effect 'can be ignored for the purposes of this discussion'. It can be treated as if it does not exist.
But woe betide you if you try to make this assertion to a politician....