Among the "petitions for reconsideration," aimed at getting the EPA to re-consider its endangerment finding on CO2, this one by the Pacific Legal Foundation focuses specifically on the fact that the authors of CRU e-mails make it clear that they don't believe themselves in some of the basics of the global warming theory they are known for.
That's the approach I would take. For some reason, they gave every appearance of being very confident in their published work, TV appearances, etc., but the e-mails show something quite different. The science is unsettled, not settled. There's not necessarily anything wrong with that, but we've had a lot of dishonesty about it. See also Phil Jones specifically on the medieval warming period. This is really what the debate about the "hockey stick" is all about. If there was a medieval warming period comparable to the twentieth century, then it was presumably natural, not man-made; it may have had little or nothing to do with greenhouse gases; and there is no record of people whining that their farms in Tennessee were not as green and lush as they used to be.
h/t Climate Audit.