DUDE, IT'S ABOUT AESTHETICS, NOT SCIENCE:

What do we want? An extremely tiny reduction in Canadian fossil fuel emissions! When do we want it? Eventually!

"To an increasingly disillusioned environmental movement," environmental activist Bill McKibben writes in the Huffington Post, "Keystone looks like a last chance." It may be a last chance for the movement McKibben has helped lead -- he has spent several years organizing activists to single-mindedly fight against approval of the Keystone pipeline -- but Keystone is at best marginally relevant to the cause of stopping global warming. The whole crusade increasingly looks like a bizarre misallocation of political attention.

My view, which I laid out in a long feature story last spring, is that the central environmental issue of Obama's presidency is not Keystone at all but using the Environmental Protection Agency to regulate existing power plants. That's a tool Obama has that can bring American greenhouse gas emissions in line with international standards, and thus open the door to lead an international climate treaty in 2015. The amount of carbon emissions at stake in the EPA fight dwarf the stakes of the Keystone decision.

Estimates differ as to how much approval of the Keystone pipeline would increase carbon emissions, but a survey of studies by the Congressional Research Service found that the pipeline would add the equivalent of anywhere between 0.06 percent to 0.3 percent of U.S. greenhouse gas emissions per year. By contrast, the Natural Resources Defense Council's proposal for EPA regulations would reduce U.S. emissions by 10 percent per year - 30 times the most pessimistic estimate of Keystone's impact.

Of course, it's far from clear Obama will settle on a regulatory proposal as aggressive as the NRDC's. But that's just the point. Even slight gradations in the strength of possible EPA plans matter more than the whole fate of the Keystone pipeline. And yet McKibben and tens of thousands of his followers are obsessed with a program that amounts to a rounding error at the expense of a decision that really is the last chance to stop unrestrained global warming.

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