There’s an ongoing dispute on this question. The post here by Dr. Roy Spencer is the most recent in this discussion. I very much appreciate Dr. Spencer’s work on global temperatures (though I’ve never met him in person).
I’ve read Dr. Spencer’s explanation before and did not find it very persuasive. The experimental evidence is new to me. However, I’m still puzzled by this explanation and interpretation of the experimental data presented by Dr. Spencer. (There are other factors beyond the second law of thermodynamics at work here.)
I decided to ask a heat transfer expert (an experienced PhD mechanical engineer) with no dog in this fight to review these explanations and comments and give me an informal reaction. The response back to me was the following:
“I scanned quickly through the link. Any system has to follow the conservation of mass and energy (can be combined as in nuclear engineering). He is relying on some correct radiation principles. But he is clueless about the effects of reflectivity and that thermal imaging does not give accurate temperatures. “
I’ll be meeting with this expert to discuss the issue further and perhaps collaborate on a future experiment of our own. Dr. Spencer’s experiment is interesting but does not resolve the difficulties I had initially with the explanation provided.
Though I disagree with him on this matter I wish Dr. Spencer well in his future work.