Joanne Nova is an Australian skeptical climate blogger whose blog is quite a popular link from the vast universe of such blogs. The link above takes you to a post that I'd never expected to see there. A guest blogger explains that the the Greenhouse Effect, or downward longwave radiation makes the Earth's surface warmer than it would otherwise be and, in so doing, does not violate the Second Law of Thermodynamics.
One statement (though far from the most general) of this most fundamental of physical principles is the Clausius formulation: No process is possible whose sole result is the transfer of heat from a body of lower temperature to a body of higher temperature. Many skeptics simply state that a cooler atmosphere warming a warmer Earth is in violation of this law and thus the Greenhouse Effect is falsified and no further discussion is necessary.
Of course, this is incorrect. The wonderful site Science of Doom has a series of articles that explain this thoroughly, but the naysayers will not be dissuaded. I'm somewhat amazed that there's a glimmer of acknowledgement of reality at Joanne's site.
And, in the intervening few days since I started this post, Joanne received so many comments to her post above that she started another thread where she sensibly replies to Joseph Postma's paper and comments. This development actually seems to me, in some small way, to be hopeful.