Coal's Law

I have long that a $1/gallon increase in the tax of gasoline would be a good idea, to encourage substitutes in consumption and production. I wonder if whether the U.S. should combat the artificial low value of the Renminbi via a tariff on coal, and encourage other exporting countries to do likewise. That would do much more for the environment than anything the Sierra Club might achieve.

Importing Coal, China Burns It as Others Stop - NYTimes.com via kwout