In November, for instance, which is the worst time in Delhi, farmers are burning stubble that is left on their fields as an efficient and cheap way to prepare for the next season of sowing. In Dhaka, the capital of Bangladesh, it's surrounded by all these extremely inefficient and dirty brick kilns. And there's very little you can do as a city about those things out there. You don't have jurisdiction. So this is everybody's problem, one that needs to be solved collectively.