@andrew adams
Re your comment of May 28, 2012 at 7:31 am:
I did study the Goody and Yung diagram and found it interesting for what it portrays. However, I think you’ll agree it has nothing to do with a controlled experiment, which in your previous comment is what you are claiming has been conducted. Rather, it shows that IR measurements of Earth have been taken in order to gather evidence to support an hypothesis (the hypothesis being that atmospheric CO2 affects Earth’s climate). This type of measurement does _NOT_ constitute an experiment!
And I don’t think you are justified in the conclusion you draw, that “this [Goody and Yung diagram] proves that CO2 does have a measurable effect on the amount of LW radiation emitted at the top of the atmosphere”. What the diagram shows to me is that CO2 is in fact acting as a greenhouse gas in Earth’s atmosphere. The diagram is strong evidence that CO2 affects the spectral content of LW radiation emitted at the top of the atmosphere. But it is weak evidence that CO2 has, per your conclusion, a measurable effect on the amount of LW radiation emitted at the top of the atmosphere. In fact, from what I understand of the arguments put forward regarding energy balance, proponents of AGW seem to suggest that GHGs do not at all alter the amount of LW radiation leaving the TOA.