Via Newsbusters. Conservatives demand an explanation, and an explanation they shall have:

I completely understand why many of you would have questions about this, so I want to take this opportunity to explain my reasons. First of all, I want to be clear: I don’t think that we have conclusive proof of global warming. And I don’t think we have conclusive proof that humans are at the center of it.

But here’s what we do know. There is an important debate going on right now over the right energy policy, the right environmental policy, and making sure we do the right things for our future and the future of our children and grandchildren. Conservatives are missing from this debate, and I think that’s a mistake. When it comes to preserving our environment for future generations, we can’t have a slogan of “Just yell no!”

I think it’s important to be on the stage, to engage in the debate, and to communicate our position clearly. There is a big difference between left-wing environmentalism that wants higher taxes, bigger government., more bureaucracy, more regulation, more red tape, and more litigation and a Green Conservatism that wants to use science, technology, innovation, entrepreneurs, and prizes to find a way to creatively invent the kind of environmental future we all want to live in. Unless we start making the case for the latter, we’re going to get the former. That’s why I took part in the ad.

As I’ve said before, this is just the sort of logic lefty environmentalists should be encouraging. But, er, isn’t he being disingenuous in saying the jury’s out on man-made global warming when he called for “urgent” steps to reduce carbon emissions in his debate with Kerry last year? The two positions aren’t contradictory — he may simply be taking a “better safe than sorry” approach — but doubtless many of the people e-mailing him are global warming skeptics and he’s leading them to think he himself is more skeptical than he probably is.