Bill McKibben, author and founder of the international environmental organization 350.org, says that without a global campaign to curb climate change, the ecological devastation of our warming climate will make our planet uninhabitable. His appeal to citizens and policy-makers, the seventh video in the series "Peak Oil and a Changing Climate" from The Nation and On The Earth Productions, is a call to action as much as it is a sobering account of the damage we’re already doing to our environment.

It’s a “crisis breaking over our heads at this moment,” he says as he points to wildfires in Russia and flooding in Pakistan as examples of the severe weather that will continue, and intensify, if we continue to ignore climate change. Failing to rein in the carbon in our atmosphere will mean more than just inhospitable weather. It also threatens global food production: “If we allow the temperature to increase anything like what people are projecting, we’ll see grain yields fall by a third or more, simply because it will be too hot for things to grow,” he says. “If it rains every day in a row for 30 days, you’re out of luck, you are not growing anything. That’s the kind of world we are building.”

The most important policy change crucial to curbing this crisis, he says, is to force fossil fuel companies to pay the price for the damages they inflict on the environment. If the environmental movement harnesses mass action and civil disobedience tactics to their advantage, there’s still a chance, McKibben says, that the earth’s citizens can convince policy makers to crack down on big polluters.

Go here to view last week’s video, Noam Chomsky explaining how climate change became a "liberal hoax." Go here to learn more about "Peak Oil and a Changing Climate," and to see the other videos in the series.

—Sara Jerving