McKibben protesting the Keystone XL. (Photo by Emma Cassidy, Tar Sands Action.)

Last spring, almost no one outside of Nebraska had heard of the Keystone XL pipeline. As late as October, when the National Journal surveyed 300 “energy insiders” in D.C., 91 percent predicted that the Obama administration would approve the permit for the pipeline. TransCanada stacked 1,700 miles of pipe along the proposed route, so confident was the company of victory.

Today, the State Department and the president denied the permit for the pipeline. It’s one of the rare days in the 20-year climate fight when scientists can smile and Big Oil has to frown. Because citizen activists around the country were willing to put their bodies on the line, and because the environmental movement worked with rare unity and coordination, a done deal has come spectacularly undone.

There are no permanent environmental victories, certainly not this one. TransCanada (or any other company) is free to reapply for a new permit, though I imagine this time the State Department process will be conducted with more transparency and less favoritism. And of course the biggest caveat of all: Even if every drop of tar-sands oil remained safely in the ground, we’ve still got more than enough coal and gas and oil to crash the climate system.

But people stood up, and then Barack Obama stood up. He stood up to very naked threats: Last week, the head of the American Petroleum Institute promised “huge political consequences” if he didn’t go along. They have the money to make good on that threat, so this decision was not just right but brave. It wasn’t the conciliatory Obama people have complained about so often.

We know Big Oil won’t give up easily — their harem of congresspeople is still at work trying to push the pipeline through. We’re going to tackle them next, beginning this coming Tuesday, Jan. 24, when 500 “climate referees” in black and white stripes will descend on the Capitol to blow the whistle on the whole corrupt system. Sign up for the action.

This fight will go on throughout the lifetimes of those of us now alive; the battle against global warming is the largest humans have ever undertaken. Which is why the occasional small victory looms so large.