Keystone XL: Game over?

RealClimate writes Keystone XL: Game over? "Jim Hansen has said that if the Athabasca Oil Sands are tapped, it’s “essentially game over” for any hope of achieving a stable climate. The same news article quotes Bill McKibben as saying that the pipeline represents “the fuse to biggest carbon bomb on the planet.” Others say the pipeline is no big deal, and that the brouhaha is sidetracking us from thinking about bigger climate issues. David Keith, energy and climate pundit at Calgary University, expresses that sentiment here, and Andy Revkin says “it’s a distraction from core issues and opportunities on energy and largely insignificant if your concern is averting a disruptive buildup of carbon dioxide in the atmosphere”. There’s something to be said in favor of each point of view, but on the whole, I think Bill McKibben has the better of the argument, with some important qualifications. Let’s do the arithmetic."