The United States and China appear to be moving in opposite directions in their approaches to climate change with the United States withdrawing from the Paris Agreement while China vows to make itself a global leader in new, green technology. In a new book, Titans of the Climate: Explaining Policy Process in the United States and China, climate policy experts Kelly Sims Gallagher and Xiaowei Xuan examine the structural differences in how the two countries approach climate policy, and outline the political and economic challenges that prompt, or restrict, environmental cooperation. On January 24, Kelly Sims Gallagher discussed her new book, and offered her analysis of the future of climate and environmental policy in the two largest carbon emitters.