It is a pleasure to set my milk crate down and clamber on top, the better to spread the news of the burgeoning movement to fight climate change—a movement somewhat different from the environmentalism of the last couple of decades.

That environmentalism, centered in the big green groups of Washington, D.C., has been noble, hard-working, and unsuccessful in the task of containing climate change. Congress, which once passed laws like the Clean Air Act, has engaged in a 25-year effort, largely bipartisan and entirely successful, to do nothing about global warming. Despite repeated warnings from the planet’s eminent scientific bodies, the fossil fuel industry—heaviest of spenders on elections and lobbying—has carried the day, blocking significant efforts.

The environmental movement has reacted in many ways, two of which are coming to a head. One is to play inspired defense, fighting particular bad projects on the ground. The success in blocking many proposed coal-fired power plants has dimmed the industry’s prospects. The largest of these defensive fights has been against the proposed Keystone XL pipeline, which would transport tar sands oil from northern Canada to the Gulf of Mexico.
The Keystone fight led to the largest civil disobedience action about anything in 30 years in this country (1,253 arrested in D.C. over two weeks in the summer of 2011), the largest demonstration outside the White House in President Obama’s first term, and the largest one-day outpouring of e-mail to the U.S. Senate. As a result the president delayed approval of the pipeline for a year. Now that the election is over, he has promised a decision this spring—so, on February 17, what was described as the largest environmental rally in a generation took over the National Mall.

This is a critically important campaign. The country’s top 18 climate scientists have explained why Keystone is a disaster, and 10 Nobel Peace Prize laureates have come together to urge its defeat—this will be the truest test yet of people power versus the money behind fossil fuel.

But the Keystone battle is still playing defense. And it’s obvious why defense isn’t enough: there are simply too many pipelines, too many coal mines, too many fracking wells, to stop them all one by one. We need to go on offense against this industry.

Which is why it is unmitigated good news that a movement has exploded across American campuses over the past three months—a movement demanding that colleges sell their stock in fossil fuel companies. All of a sudden, students on 210 campuses are fighting for divestment—and on a few they’ve already won. The New York Times, in what became the most e-mailed article of the week in which it was published, wrote that the campaign could “force climate change back on to the nation’s political agenda.” A few days later Time magazine ended its account like this: “University presidents who don’t fall in line should get used to hearing protests outside their offices. Just like their forerunners in the apartheid battles of the 1980s, these climate activists won’t stop until they win.” Harvard undergraduate Chloe Maxmin, after watching her fellow students vote 3-1 in favor of divestment, wrote in The Nation that “this campaign is engaging more students than any similar campaign in the past 20 years.”

Those students are remarkably sophisticated. They know divestment won’t bankrupt Exxon, but they also understand that its profits depend on its ability to intimidate politicians. The day when, like all other businesses, they’re forced to pay to put out their waste is the day their finances will collapse. These industries have spent a small fortune in D.C. making sure they can keep pouring carbon dioxide into the atmosphere for free, which has been the basis of the large fortune they have accumulated. On college campuses, religious denominations, and in other places where reason still reigns, we’re doing our best to revoke their social license, to make folks realize they’ve become rogue industries that we tolerate at our peril.

That peril is now very great—last year the great Arctic ice sheet conclusively melted, leading NASA scientists to declare a “planetary emergency.” But lest this soapbox rant sound too much like an “end is near” prophecy, let me say instead: the battle is finally joined.

Bill McKibben is the Schumann Distinguished Scholar at Middlebury College, the founder of 350.org, and the author of Fight Global Warming Now: The Handbook for Taking Action in Your Community (St. Martin’s Griffin) and other books.