"In China's rich northern coal belt, hundreds of underground fires are burning upward of 200 million tons of coal each year, about 20 percent of the nation's annual production. The fires produce nearly as much carbon dioxide, the main gas linked to global warming, as is emitted each year by all the cars and small trucks in the United States."
Boy, I'd like to tattoo that quote on some tree hugger's forehead.
ITC has an entire site devoted to the 3rd world coal fire problem, including this article on China, and this really great map of Chinese coal field fires.
EPHnet also has a good article, and finally I pulled these two off the BBC: link 1 and link 2.
Happy reading.