Bill McKibben is the founder of 350.org and the author of several books, his most recent is Oil and Honey: The Education of an Unlikely Activist.
McKibben spoke with WMUK's Gordon Evans ahead of his appearance at Western Michigan University on Thursday, as part of the Center for the Humanities Changing Climates Series.

350.org takes its name from what McKibben calls the most important number in the world. He says it's based on scientists' belief that a carbon dioxide level below 350 parts per million is needed to maintain life as we know it. Levels are currently around 400 parts per million.
McKibben says he's learned about the political process in his time as an activist and says he has found that money, not science is what drives policy.
As clean up continues three years a massive oil spill on the Kalamazoo River, McKibben says continuing to look for fossil fuels will mean more drastic measures such as hydraulic fracturing also known as "fracking." And he says it means bringing in "tar sands" oil, which McKibben says "the dirtiest of the dirty."