Several months ago, we mysteriously began receiving a subscription to Rolling Stone magazine, a publication that isn't always as vapid as the cover story might suggest. Take, for instance, the August 2nd issue, which featured Justin Beiber on the cover wearing a sleeveless T-shirt next to the headline "JUSTIN BIEBER HOT READY LEGAL." After carefully clipping out that story for our candlelit Bieber shrine, we stumbled upon another article that, incongruously, wasn't related to Steven Tyler or Ke$ha. Called "Global Warming's Terrifying New Math," the lengthy article, by Bill McKibben, is a riveting fresh look at the biggest crisis humans have failed to do anything about.

Confirming the worst of what we already knew and feared with persuasive authority, McKibben, an author and environmentalist who heads the international environmental organization, explains that "to grasp the seriousness of our predicament, you just need to do a little math. For the past year, an easy and powerful bit of arithmetical analysis first published by financial analysts in the U.K. has been making the rounds of environmental conferences and journals, but it hasn't yet broken through to the larger public. This analysis upends most of the conventional political thinking about climate change. And it allows us to understand our precarious—our almost-but-not-quite-finally hopeless—position with three simple numbers." Spoiler: These numbers will scare the shit out of you. After reading his Rolling Stone article, we sent McKibben some questions, which he graciously answered via email.

Your recent Rolling Stone article was extremely alarming, and it comes as the United States is experiencing such volatile weather. Scientists are often reluctant to connect weather patterns to the broader patterns of global warming. Do you see a connection? Yes, and scientists are being increasingly vocal about the connection. You can't do things like melt 40% of the Arctic summer sea ice without it having implications for the planet. Even more consequentially, it's always important to remember that warm air holds more water vapor than cold—with the atmosphere about 5% wetter on average, the system is constantly primed for both drought and deluge.

Why do you think President Obama has proven to be such a disappointment at this critical juncture for the future of civilization? Well, he couldn't do anything too grand because the GOP Congress wouldn't let him—that's why real progress at Copenhagen was off the board. And when it's been easy, he's done some good things—a supine auto industry put up no resistance to increased gas mileage standards. But it is sad to see the "all of the above" energy strategy—I fear it's mostly a concession to the political power of the planet's richest industry in a post Citizens-United world.

What are the most effective ways for U.S. citizens to take action in a last ditch attempt to pull the planet "back from the brink," as you put it? We're going to launch, the day after the election, a huge roadshow around the country, 20 cities in 20 nights. We'll be trying to spur a full-on campaign of divestment from the fossil fuel industry on campuses, in churches, in pension funds. Hopefully folks will start to understand that this is the moral issue of our times.

If we continue failing, what do you expect the world to look like in 20 years? Well, hotter for sure (even if we 'succeed' it's going to be somewhat hotter). But I imagine the thing we may notice most is more erratic, violent weather.

What about 40 years from now? I fear we should expect not linear increases in trouble, but something steeper.

What's the latest on the Keystone pipeline? On the so-called southern leg, people are preparing civil disobedience to stop the laying of pipe. On the northern section, which would bring in new tar sands oil from Canada, the State Dept is preparing a new environmental review. So far it's not completely clear whether they're planning a sham like last time, or whether they will do a serious review of the climate consequences.

The big oil interests you have organized against are extremely wealthy and powerful. Have you ever feared for your safety? Well, I get a lot of weird email, it must be said. But, I'm a Methodist—on we go, you know.

At this moment in time, if you had to guess, who are the five most dangerous people in the world, in terms of global warming?
Well, probably the fossil fuel barons who are most politically active in making sure we never change politically to deal with this crisis. I think the Koch brothers have earned their place at the top of the list.

If you could say anything to one of these individuals, what would it be? If you are going to try and take away the future, we're going to try and take away your money. At we're getting set to launch a full-on divestment campaign, reminiscent of the fight against apartheid a generation ago.

How do you resist falling into despair? I don't always, but in the last four years, since we started, I've met so many people around the world who are willing to fight. Many are from countries that have done nothing to cause this problem—if they can stand up, I guess I can too. I'm not an activist by background or temperament, but I do find that fighting makes it easier not to obsess about our trouble. In a weird way, when you're in the middle of the game you worry less about who's winning maybe.

Have you ever been seated at dinner next to a staunch climate change denier, or gotten into a similar social situation? If so, how did that go? Sure. In most cases, I find that they're basing their opposition on ideology, not science (because there's not much science to base it on). So, I try to explain why it's a very radical thing to change the chemical composition of the atmosphere, and an oddly conservative one to try and keep it something like the way we found it. If that doesn't work—if they just keep insisting that humans can't possibly affect the climate—I usually just say 'I hope you're right.' Because I think the real problem is not convincing the hard-core deniers; it's activating the people who do know there's a problem but just aren't getting involved.