THE BIGGEST PROBLEM we face when we confront global warming is that fossil fuels produce carbon dioxide. We need to reduce emissions to limit warming, but we have no easy and cheap alternatives to fossil fuels. That’s a big problem, but it is not humanity’s first big problem. When we look back in time, we seldom fixed big problems by telling people to live with less of everything they wanted. And for a good reason: it is a hard sell. Instead, we typically managed to solve big problems through innovation.
