It’s a cold fall evening in Columbus, Ohio, but nearly a thousand people are ready to contemplate the consequences of man-made global warming. A tall, slender man strolls on stage and the crowd instantly rises, applauding for nearly two minutes, much to the discomfort of the humble speaker. Dressed casually in running shoes and slacks, with an unpretentious digital watch on his wrist, stands Bill McKibben, a man who has declared war on the most profitable industry “in the history of money.”

McKibben, known as “the nation’s leading environmentalist,” came to Columbus on Tuesday as part of a 21-city, 26-day tour called Do the Math. Organized by the global environmental group 350.org, the tour is an extension of McKibben’s phenomenally popular article “Global Warming’s Terrifying New Math” which appeared in the July issue of Rolling Stone (the same one, McKibben jokes, with Justin Bieber on the cover). Earning over 124,000 Facebook likes and 13,400 related tweets, the article was described by one journalist as “among the most widely read single articles on climate change…ever.”

The tour has been riding this momentum, selling over 24,000 tickets and performing 17 sold-out shows with a number of special guests, including author Naomi Klein, filmmaker Josh Fox, and musical acts like DJ Spooky. It may be more than you’d expect for something that’s got “math” in the title, but McKibben isn’t talking about just any numbers; he’s talking about the three most important numbers of the climate crisis and using them to launch a campaign that might just save the world.

The first number, 2 degrees Celsius, is thought to be the maximum temperature increase permissible without causing runaway climate change. The second number, 565 gigatons, is the amount of carbon scientists say humanity can burn without exceeding the 2°Celsius limit. And the final, perhaps most terrifying number — 2,795 gigatons — is the amount of fossil fuel that companies possess in their known reserves and plan on burning.

Simply knowing these numbers, however, isn’t going to stop climate change. That hope died a long time ago with people like McKibben, who in 1989 wrote the first book on climate change for a general audience. As he noted during his talk, McKibben has rejected the idea that people would “read my book, then change.” Admitting he would “rather be home typing,” McKibben has nevertheless transcended his hesitancy and emerged to spearhead a millions-strong global grassroots organization.

That’s why the real aim of the tour is to ignite a movement that “will send shockwaves” through the fossil fuel industry. “We need to make the case, quickly, that the fossil fuel companies should lose their social license,” McKibben said. To accomplish this, 350.org has initiated a nationwide fossil fuel divestment campaign to focus on the endowments of colleges and universities. As the group’s “Fossil Free” activist guide explains, divestment “means getting rid of stocks, bonds, or investment funds that are unethical or morally ambiguous.” The demands for universities are simple and unequivocal: “freeze new fossil fuel investment immediately” and “full fossil fuel divestment within five years.”

Since fossil fuel companies have “bought the silence of our politicians and filled our airwaves with misinformation,” McKibben contends activists need to pressure society by nontraditional means. Higher education has over $400 billion invested in endowments and nearly every university today is, at least nominally, committed to sustainability. Divesting from unethical energy sources forces institutions to be honest. Who better than students to hold universities accountable? Students are among the most informed about climate change and their future is directly threatened. Campuses are prime environments for educating, organizing and translating ideals into action.

Yet higher education is just one part of the catalyst for a broader offensive against fossil fuels. 350.org is also pressuring religious institutions, foundations and state and private pension funds. The aim is to make investing in fossil fuels socially reprehensible, which may lead to significant political action. Successful divestment campaigns will send a clear message to Wall Street and society that fossil fuel companies are unsustainable “risky investments.” As anti-apartheid hero Desmond Tutu explained in a video for the crowd, “The corporations understand the logic of money, even when they aren’t swayed by the dictates of morality.”

Much like the present political impasse for climate activists, anti-apartheid activists in the 1980s could gain little traction in Washington, D.C., so they developed alternative strategies. Tens of thousands of students successfully pressured 155 American universities to divest their endowments from companies supporting South Africa’s apartheid regime. Fearful of billions in lost revenue, by 1987 roughly 200 companies had withdrawn from South Africa (the same number of publicly-traded companies, coincidentally, that hold the majority of the world’s fossil fuel reserves). Student pressure also precipitated legislative action. By 1991, 28 states, 24 counties and 92 cities had adopted legislation imposing sanctions on South Africa. The campaign played a crucial role in destabilizing the apartheid regime and the transitioning to a democratic South Africa. “A similar strategy,” 350.org advises, “can help us topple the fossil fuel regime.”

Fossil fuel divestment organizations have emerged at more than 130 different universities and already two colleges — Unity and Hampshire — have committed to divestment and started to shed their portfolios of fossil fuels. Meanwhile, the city of Seattle is formulating a comprehensive divestment plan and the undergraduate student body at Harvard also passed a resolution to divest with an impressive 72 percent of the vote. Yet the Board of Trustees quickly commented that they have no such plans. As McKibben notes, no one said it would be easy to defeat the most profitable industry in the history of money.

On my campus, Ohio University, we began organizing a month ago. With several like-minded individuals, we formed a steering committee with the aim of bringing as many students as possible to the “Do the Math” tour in Columbus. 350.org provided assistance by sending a representative to help us, designing flyers, organizing materials and offering free tickets for students. To raise funds, we asked for junk food donations outside of university convenience stores and then sold the food in front of the bars. We succeeded in providing free transportation and free tickets for dozens of interested students.

Next week we are meeting to form a permanent campus organization, Fossil Free OU, and begin the hard work of building a strong base of allies on campus. With 350.org’s continued support, we have already started circulating a campus-wide petition and look forward to hosting debates, screening movies and inviting informed professors to lecture. Eventually, our aim is to meet with university officials, deliver our petition to the university president, publish editorials in the local newspapers and begin holding creative demonstrations.

While the campaign draws much support and energy from college students, we want to utilize the talents of a diverse coalition. Because alumni play an important fiscal role for universities (as McKibben noted, colleges have a “special affection” for them), we will invite prominent alumni to speak out by writing letters, publishing ads in our alumni magazine and even withholding gifts. Gaining support from tenured professors will also be essential (as McKibben quipped, this is “what tenure was made for”).

Hopefully our coalition building, consciousness raising and pressure will succeed in convincing our Board of Trustees, but most likely we will have to escalate our tactics to involve nonviolent direct action and civil disobedience. As McKibben explained with grim honesty at the end of his lecture, some of us “may need to go to jail before this is all over.”

For some that is still a tough reality to swallow, but we must remember, as McKibben noted, “There is nothing radical about what we’re asking for. What is radical is the fossil fuel industry irrevocably changing the climate of Earth.” Ultimately, he concluded, “our vision is deeply conservative and our only job is to check that radicalism.” But we can’t do it working alone. We have to “fight shoulder to shoulder” if we want to win.