http://online.wsj.com/article/SB124414770220386457.html"While there is almost certainly as much coal in the ground as Mr. Warholic's Energy Information Administration believes, relatively little of it can be profitably extracted. Last year, the U.S. Geological Survey completed an extensive analysis of Wyoming's Gillette coal field, the nation's largest and most productive, and determined that less than 6% of the coal in its biggest beds could be mined profitably, even at prices higher than today's.
"We really can't say we're the Saudi Arabia of coal anymore," says Brenda Pierce, head of the USGS team that conducted the study.
No one says the U.S. is facing a coal shortage. But the emerging ranks of "peak coal" theorists argue that current production levels may be unsustainable and, if anything, create a false sense of security. David Rutledge, an electrical-engineering professor at the California Institute of Technology who has studied global coal production, figures the U.S. has about half as much recoverable reserves as the government says, which would work out to about 120 years' worth."
Good.