The Paris climate agreement represents an enormous breakthrough in the long struggle to come to grips with global climate change. For the first time, developed and developing nations – 195 in all – agreed to cut the pollution that is causing rapid and dangerous changes to our environment. But now the hard work begins in earnest. If the Paris Agreement acts as a catalyst for a transformational change in the way we power the world economy, success is within our grasp. If, however, nations treat their commitments as an end in themselves, we will fall short. Fred Krupp, president of Environmental Defense Fund and a preeminent U.S. climate leader, assesses the post-Paris landscape, including the Supreme Court’s decision to stay the EPA’s Clean Power Plan, and outlines the keys to getting where we need to go: momentum toward clean energy in the United States, the rise of China as a climate problem solver, and the necessary ingredients for comprehensive climate policy.