Too many of the AGW religious are like him, and nothing short of the destruction of the planet is going to convince they are wrong. It is like the Daffy Duck cartoon (the one where he is auditioning for a spot on a show and blows himself up). They can only be proved wrong once - but there will be no one around afterwards to say "see, we told you so".
I read an interesting article recently by Andrew Coyne, and I quote "The error here is not only scientific. It is also political. If your desire is to persuade the unpersuaded among the general public, the very worst way to go about it is to advertise your bottomless contempt for your adversaries."
It doesn't matter what side of the debate that you are on, but if your basic argument is, "I'm so smart, you're so dumb, and I'm going to hit you over the head with my opinions until you get it", well that is not likely to be the argument that persuades me.