Nina Easton‘s latest Fortune magazine column suggests that critics of the controversial Keystone pipeline should have spent more time considering the likely outcomes of their opposition.

Here’s what environmental activists have to show for their success in blocking construction of the Keystone XL pipeline over the past three years: an uptick in oil traveling by rail and trucks. North Dakota officials estimate that the state’s highways are being pounded by 300 to 500 additional semi trucks a day, belching fumes and adding to traffic fatalities.

That’s the kind of fallout from a rigid enviro-agenda that makes Gary Doer, the Canadian ambassador to the U.S., shake his head with bemusement. “The fundamental argument that if you stop the pipeline you stop oil from being developed is just wrong,” he points out. “Oil gets to market.”

It sure does, and with a North American oil boom well under way, that black gold is already end-running President Obama’s reluctance to bless a critical stretch of pipeline that would transport oil from Alberta to Texas refiners on the Gulf, with on-ramps in North Dakota and Montana.

It’s now been five years since TransCanada Corp. filed its cross-border application, and Keystone XL remains in limbo. The State Department has completed four reviews — and is on its fifth. Its 2011 report concluded that the pipeline would have “no significant impacts” on the environment. Bipartisan majorities in both houses of Congress support it. And pipeline construction is a rare point of agreement between the U.S. Chamber of Commerce and the AFL-CIO, which is eyeing the 42,000 direct and indirect jobs coming online during the construction phase.

But environmental groups, claiming the moral high ground, have poured millions into a campaign to pressure Obama: Actors such as Robert Redford have opposed it, and billionaire hedge-funder Tom Steyer launched a million-dollar TV ad campaign in September. That’s what gets under the skin of Doer, who openly criticizes an activist “industry” based on self-sustaining fundraising. He asks if any of those West Coast elites have ever even driven down North Dakota’s truck-clogged highways. More to the point, he complains, the activist community ignores the advantage of pipeline vs. rail, which leaves a bigger carbon footprint and the potential for accidents — like Quebec’s devastating derailment of a train ferrying tankers of crude. “They delayed Keystone in 2011, and in 2012 train transportation for oil went up 46%,” he says.