There is an 8-billion-ton hole in how advanced countries like the United States think about addressing climate change. It’s equal to one and a half times all U.S. annual CO2 emissions and is getting bigger every year. It represents nearly 25% of total CO2 emissions globally, and there are currently no policies anywhere in the world specifically designed to mitigate it. If we are going to adequately respond to climate change, we must close the carbon loophole.