ThinkProgress: A group of leading law professors who work on climate have published a game-changing new legal analysis. It finds that the Paris climate agreement unlocks a previously unused Clean Air Act provision that enables broad authority to use market-based mechanisms to reduce carbon pollution nationwide. Last December in Paris, the U.S. committed to cut greenhouse gas emissions 26 to 28 percent compared to 2005 levels by 2025. That target appears more than achievable given a variety of existing policies,...