Climate Sensitivity
I suppose there is a sort of Anna Karenina principle for scientific error: every correct scientific argument is the same, but every erroneous argument is erroneous in its own way, but there are some general strategies: put in some correct stuff, put in some related equations but at the critical moment equate some things that aren't actually equal or derive something from an inappropriate equation. Above all, though, make your argument complicated, so that it's really hard to see exactly where you went wrong. In this last respect I can't say that ex-Professor Motl's Post is a model, because he's really quite clear in his argument and it's pretty obvious exactly where he goes off the tracks in his calculation of climate sensitivity. Of course he does emit a lot of smoke after that point, but it's way too late too hide the dirty deed by then. To set the scene, let's remember that CO2 causes planetary warming by increasing the outgoing impedance to radiativ...