Header shamelessly stolen from Coby. But his post is so wonderful that I can’t help re-saying it.
So: Roy Spencer says that the basic greenhouse effect mechanism is sound; or perhaps, more weakly, that the basic mechanism is phyically possible. You might think that is not very strange, after all it isn’t really very dificult. But alas so many poor innocent young and not-so-young wannabe “skeptics” have been exposed to the denialist meme “cold things can’t make warm things warmer; the upper atmophere is colder than the surface; therefore the atmosphere doesn’t heat the surface; therefore the GHE is wrong” that even Spencer, long a poster boy for the sketpic “side”, gets savaged by some ignorant drivel in the Canada Free Press.
As Spencer says in his comments,
The reason I am addressing this issue is that there is an increasing number of people who are advancing the notion that there is no such thing as “back radiation” (or that “more CO2 is incapable of causing any warming because…”), and as a result I am deluged with e-mails from them and the public asking me for my opinion.
So, all credit to him, he has actually started doing some experiments, although (as he points out) it is all a bit odd, because you can just as easily point an infra-red thermometer upwards at night.
If you actually want some good facts and discussion on the “back radiation” stuff, then Science of Doom has a good post [Update: and even more excuciating detail on the key error in part III], and followups – people really are astonishingly reluctant to accept something very simple. If you can cope with a bit of maths, then [[Idealized greenhouse model]] will help. If you can’t cope with maths, then it really is very simple: the earth is warmer than it otherwise would be because it receives radiation from two sources: the sun and the atmosphere.
This is all yet another example of the “Dumb America fallacy” – people too ignorant to know how ignorant they are. Yes, I know, daarhling “skeptics”, if I was all out to convert you I’d omit that last bit.
[Update: see-also Our Deliberate Slide into Ignorance]