Rolling Stone interviews Bill Gates, and one focus for the world's richest man is climate change, which he discussed with Charles Koch: "He's a very nice person, and he has this incredible business track record. He was pointing out that the U.S. alone can't solve the problem, and that's factually correct. But you have to view the U.S. doing something as a catalyst for getting China and others to do things. The atmosphere is the ultimate commons. We all benefit from it, and we're all polluting it. It's amazing how few problems there are in terms of the atmosphere. . . . There's just this one crazy thing that CO2 hangs around for a long, long time, and the oceans absorb it, which acidifies them, which is itself a huge problem we should do something about."