Climate change is threatening our world, that much is becoming more and more apparent every year. And often it seems like little is happening on a policy level to address this impending crisis. But, in 2008, a group of states in the Northeast managed what seemed nearly impossible. They put in place a robust, multi-state system to put a price on carbon. Professor Leigh Raymond explains how they were able to overcome obstacles that have doomed so much other climate policy, how exactly this system works, and what lessons can be learned for other climate proposals.