I can't see that Obama's decision to go to Copenhagen and proclaim a goal for reducing greenhouse-gas emissions amounts to much. The 17 per cent cut by 2020 he is talking about is in line with the reductions foreseen in the bills now in Congress, but those bills are stuck. Perhaps it would be unseemly not to turn up at all--since he will be in the area, collecting his Nobel prize for most promising world leader--but he cannot disguise the fact that, despite all the expectations aroused earlier, he is going empty-handed. It isn't the world he needs to convince on global warming, it is the electorate back home.

This is all the harder since the climate science email dump, which showed leading experts--people calling for enormous changes in how the world's economies work--discussing ways to keep their data private, manipulate public opinion, and deny dissenters access to the professional literature. (None of those emails surprised me, by the way. When it comes to public relations, the climate-science cabal is its own worst enemy. I'm surprised so many people are surprised.)

I'll return to this subject--but I continue to believe, in any case, that quantitative targets are not the way to go. Despite the totalitarian instincts of some climate scientists, the problem is real and needs to be addressed. Kyoto, however, proved beyond a doubt that the quantity-targetĀ  approach is too complicated. Convergence on a global price of carbon makes much better sense, not just in economic terms, but as a matter of practical diplomacy as well. The Senate bill nods in that direction by contemplating a price collar--in effect, a target for prices not quantities. That is the way to go, but the diplomacy needs to be reorganised around the idea. The administration should be leading that effort, and simultaneously making its case to US voters.

I'm still thinking about whether Copenhagen is merely another pointless international sideshow, or, like the intellectual intolerance of the climate-science establishment, an actual obstacle to getting this job done. Probably the latter.

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