Air pollution has been a long-standing problem in China, but it may have reached a turning point earlier this year, after thick blankets of gray clouds enveloped Beijing and other cities for days. The health toll on the Chinese population has been staggering, and the government is finally demonstrating the volition to take the problem seriously. Watch the following video to find out how all this adds up to considerable pain for American coal exporters.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.