Libertarians and global warming

As you may be able to tell from the title (and the fact that I'm putting this up only a few minutes after a commuting post) this is a political rant. The global warming side of things does relate (slightly) to cycling though.

I fail to understand the massive opposition to the concept of climate change/global warming that persists in a lot of libertarian circles. The opposition to government mandated action on the problem I understand, that runs counter to the central core of libertarian philosophy. What I am talking about is the oft-repeated antipathy towards the idea that human may just have screwed the planet up a wee bit, and that it might be a good idea to do something about it. The most prominent person in this camp used to be Ronald Bailey, the science writer for reason. Recently though he came out as being open to the idea of man-made climate change (here for the full "saga" as he calls it). I have always felt that Bailey at least was arguing based on the science - he did not see specific scientific evidence that convinced him that human action had led to climate change, or that convinced him that the "changes" people were pointing to weren't part of a larger cycle. Fine, if you disagree with the science that's what debate and discussion is for.

What I take issue with is the trend in many libertarian circles to simply deride the idea of man-made climate change. This isn't debating on the merits, just slamming the side you don't agree with. It reminds me of the way Christopher Hitchens is when he writes about religion, muddying argument with insult. If you are going to argue against something give me a reason to think you have some substance. Otherwise you're just doing a Kerry - my own pejorative based on John Kerry's half-assed run for president where he did not once give a reason why voters should pick him, and instead based his whole campaign on reasons to not vote for Bush.