A study, led by Tad Patzek, chairman of the Department of Petroleum and Geosystems Engineering at the University of Texas at Austin, says that the world will face "peak coal" as soon as 2011. (The study defines "peak coal" as the peak in the amount of energy produced globally from coal.)

In contrast, the U.S. Energy Information Administration projects coal consumption for electricity growing more than 50 percent by 2035 unless policies are put in place to stop the growth to prevent greenhouse gas emissions.

Professor Patzek argues that the reserves estimates of the United States and other countries overstate how much coal is actually practical to mine and use. In his study, he disregards national estimates of reserves and uses a version of Hubbert’s technique for predicting peak oil. This only takes into account actual production patterns.

Other recent studies have also concluded that coal reserve estimates are often too high. Chemical engineers at Newcastle University in Australia, the electrical engineer David Rutledge at the California Institute of Technology and the German Energy Watch Group have all predicted that coal production will peak within the next couple of decades.

Professor Patzek’s study notes that its projections would mean that carbon emissions from global coal production would decline by 50 percent by 2050 – significantly below the carbon emissions scenarios produced by the Intergovernmental Panel on Climate Change.which Professor Patzek says are “based on economic and policy considerations that appear to be unconstrained by geophysics.”

The study concludes that "the global community should be devoting its attention to conservation and increasing efficiency of electrical power generation".