Donald Trump exaggerates how much coal in U.S. has been phased out

"We're practically not allowed to use coal any more. What do we do with our coal? We ship it to China and they spew it in the air."
http://www.politifact.com/truth-o-meter/statements/2015/dec/15/donald-trump/donald-trump-exaggerates-how-much-coal-us-has-been/