The Costs Of A Warming Planet

Ryan Avent accosts Manzi. Twice:

I’ll reiterate again that a) the costs of the legislation are likely overstated, b) Manzi is assuming that there will be no ancillary benefits to the legislation, and c) Manzi is assuming that after this legislation is passed there is no change in global warming policy in America thereafter, ever, for the next century. I don’t have a problem with people using Manzi’s analysis as a datapoint to consider in determining how they feel about Waxman-Markey, but you’d have to check your common sense at the door to buy his interpretation of it. You’d have to assume that the uncertain costs of an unprecedented climatic shift are likely to be no big deal and well within our ability to handle, while the rather mundane use of government policy to trim a bit off of consumption in an effort to prevent us from killing hundreds of millions of people is bound to be totally debilitating.

I'm not trying to beat up on Jim by posting all of these rebuttals to his post, but he is drawing most of the fire from supporters of the Waxman bill. I'm fairly sympathetic to Manzi's analysis and have yet to see a blogger forcefully counter his mathematical argument with another mathematical argument.

When faced with huge economic and climate uncertainties, it's hard for me to come down forcefully one way or the other. I appreciate that obliterating the planet is a a smidge bigger risk than spending too much money, but I worry about the unintended consequences of regulation, and there are diminishing returns from playing the world destruction card if your proposed legislation isn't going to fix the problem. Krugman performs this slight of hand today in his column; instead of debating the merits of Waxman-Markey, he beats up on climate deniers for 800 words. This allows him to discuss the bill without shedding light on any of the details.