It doesn't matter.
Ever since the debate over the Keystone XL pipeline exploded three and half years ago, that's been the argument from the project's liberal supporters. Sure, the oil that Keystone would carry from the Alberta tar sands is three to four times more greenhouse-gas-intensive than conventional crude. But that's not on Keystone XL, we're told. Why? Because if TransCanada isn't able to build Keystone to the south, then another pipeline will be built to the west or east. Or that dirty oil will be transported by rail. But make no mistake, we have long been assured: all that carbon buried beneath Alberta's boreal forest will be mined no matter what the president decides.