The most damning statistic about TransCanada’s Keystone XL pipeline can be found in management’s own discussion of the project: The estimated annual rate of depreciation for “Oil pipeline and pumping equipment” is “approximately 2%-2.5%.”[1] What this means is that the entire project is based on the assumption that it will be carrying the tar sands oil for the next 40-50 years.

Tar sands oil, it is broadly acknowledged, is dirty fuel. In addition to local and regional environmental impacts, the process of producing tar sands oil generates three times the greenhouse gas pollution as producing conventional North American crude.[2] Support of the keystone pipeline is therefore a commitment to supporting one of the dirtiest fuels on the planet for the next 40-50 years.

If we acknowledge the threat posed by greater storms, droughts, and temperature extremes—if we know that we will be living in an increasingly carbon constrained world, such a commitment does not make any sense. Of course, we are not going to stop consuming oil tomorrow. But it does not follow from there that we need to make a new, 40-50 year commitment to production of the most polluting form of oil.

Investment can be better directed. At minimum, enhanced oil recovery (EOR) is a way of tapping existing domestic sources with less carbon pollution than conventional oil. More importantly, investments in biofuels, electrification, and efficiency offer potentially higher returns than tar sands even prior to considering the cost of carbon pollution. But if you do consider carbon pollution, tar sands oil is not economic as compared to these choices, almost out of the starting blocks and certainly over time.

Joe Nocera, who has written in favor of approving the Keystone pipeline several times, recently noted that his last column on the Keystone Pipeline contained a serious error:

“In my column on Tuesday, I described the strategy of anti-Keystone XL pipeline activists as boneheaded. In writing about the effect of a carbon tax on Canada’s tar sands oil, I was pretty boneheaded myself. I said such a tax would likely make tar sands oil more viable. But, obviously, it would do the opposite, by decreasing demand for oil and making the already expensive tar sands oil even less economically appealing. What was I thinking?”

Joe deserves credit here for this candid admission, but let me venture to answer his question “what was I thinking?” Turns out he also favors a carbon tax as a way of making polluters accountable for carbon pollution. But, properly understood, a meaningful fee on carbon pollution would tend to undermine the economic viability of tar sands oil—over time perhaps entirely, making the Keystone Pipeline a complete waste. To be in favor of the project, he really needed to botch the logic of the policy, and so he did.

Bottom line: If you favor holding polluters accountable for pollution, there’s no rationale for going forward with Keystone’s 40-50 year commitment to dirty fuel. Joe Nocera is not the only pundit that clings to the contradiction of acknowledging the serious problem of carbon pollution, yet favoring the Keystone pipeline. It’s time for him and others to pull off the logic blinders. Denying a permit to the Keystone Pipeline should be, as he would say, “a no-brainer.”

 Chris Arndt is a private investor and a member of the NRDC Action Fund board.