"[A]s an atmospheric scientist and environmental engineer, I focus most on technologies — that’s what we think about most of what we need to be able to clean up electricity, what we need for cleaner cars. But those aren’t going to make it to market and those aren’t going to help cool the climate unless there are policies that get those to be deployed domestically. And what we do domestically isn’t enough because we’re only 1/7th of the world’s emissions, so we need diplomacy to take what we do here in the U.S. and make sure that that starts being applied in other parts of the world as well. . . . [A]s I was looking at the diplomacy [I noticed that what] the United States really gets right is being reciprocal . . . when we do something, we usually insist that our trading partners go along as well. You even hear in Congress talk about if we ever did have a carbon tax, being sure it got applied as tariffs on goods that got brought in."