There are several news articles on this.. Its about emission standards..
Yes, it is about emission standards. They've gone up and up over the years, but electrostatic scrubber technology developed for coal-burning electricity plants in our cities have kept up and today it is difficult to find any city in the country with truly polluted air. Where you do find it, it's still usually due to inversion layers you find in natural "bowls" below mountain ranges, like in Phoenix and Los Angeles.
And, yes, there are severe pollution problems in some parts of China and India. China and India need to do something constructive to battle their own pollution problems, but how does Obama's campaign to bankrupt the coal industry and jack up utility rates for Americans help pollution problems in China and India?! The United Nations may love this big crackdown, but American utility ratepayers definitely will NOT....