National Geographic: It's easy to get depressed about climate change. We've made so little progress in reducing carbon-dioxide emissions that our previous goal - to limit the rise in global temperature to 2 degrees Celsius - is almost laughable. (See: "UN Climate Report Questions Global Willpower")
But what if companies could make money from carbon dioxide, the heat-trapping gas that's the main contributor to global warming?
We're not actually so far off from turning emissions into commodities, it turns out. In...