There’s one reason why all of the environmental ills we face—climate change, poor drinking water, polluted streams—don’t always keep me awake at night. As I see it, the worse things get, the more incentive there is for some innovator to figure out a solution. Eventually, when the problems become intolerable to a critical mass of people, someone will figure out how to solve them.

Look at China, a country where air pollution in some cities has hit 20 times healthy limits. The World Health Organization advises that small particulates called PM2.5 not exceed 25 micrograms per cubic meter of air. This week, it was measured at 526. That’s the cost of rapid industrialization, apparently.

But now, a Chinese millionaire named Chen