http://blog.wired.com/wiredscience/2008/12/world-coal-rese.htmlSAN FRANCISCO, California — A new calculation of the world's coal reserves is much lower than previous estimates. If validated, the new info could have a massive impact on the fate of the planet's climate.
That's because coal is responsible for most of the CO2 emissions that drive climate change. If there were actually less coal available for burning, climate modelers would have to rethink their estimates of the level of emissions that humans will produce.
The new model, created by Dave Rutledge, chair of Caltech's engineering and applied sciences division, suggests that humans will only pull up a total — including all past mining — of 662 billion tons of coal out of the Earth. The best previous estimate, from the World Energy Council, says that the world has almost 850 billion tons of coal still left to be mined.
"Every estimate of the ultimate coal resource has been larger," said ecologist Ken Caldeira of Stanford University, who was not involved with the new study. "But if there's much less coal than we think, that's good news for climate."