Elegant rebuttal of global warming skeptic

I think this Boing Boing post illustrates an elegant rebuttal to a global warming skeptic.

Knowing that Arctic climate models are imperfect, it would be reassuring for me, if not for the scientists, to be able to write that scientists keep making grim predictions that just that don't come true. If that were so, we could follow Dyson's line that the models aren't so good and "the fuss is exaggerated". Scarily, the truth is the other way around. The ice is melting faster than the grimmest of the scientist's predictions, and the predictions keep getting grimmer. |Link|