Greenhouse Thought Experiment

Greenhouse Thought Experiment. A Guest Post from Jeff Condon. Denialists go to great lengths to misrepresent the “greenhouse” effect and direct our attention to partisan television commercials telling us that CO2 is “essential for life”. Mr. Dunning–Kruger Derek Alker, inspired by Tim Ball et. al.’s comic novel Slaying the Sky Dragon – Death of the Greenhouse Gas Theory, sent Jeff an Excel spreadsheet and a really ugly PDF that “ends the AGW scam” (again).

Apparently Derek received a geometric flash of insight into Earth’s shape. Them dumb physicists are ignoring the “back” half! Only they’re not of course…Science of Doom tries to turn the conversation back to reality on Jeff’s “No Consensus” website (sorry, I can’t write that without quotes around it).

But for us, this is Jeff’s launching point for a thought experiment about “the greenhouse”. He considers two Earths (specifically, a happy 1℃ warmer Republican Earth and a miserable colder Democratic Earth). Which will appear “warmer” to an external observer? After-all, a real greenhouse will appear warmer to an external observer. As any Physics 100 student will tell you, the answer is that the two Earths must exactly balance the radiative energy. In = out.

The interesting question is how could one Earth be 1℃ warmer than the other. Who wants to guess?