Did you know? The heat in the upper six miles of the earth’s crust contains 50,000 times much as energy as found in all the world’s oil and gas reserves combined. Despite this abundance, only 10,500 megawatts of geothermal generating capacity have been harnessed worldwide. For more information view the text and data in Chapter 5 of Plan B 4.0: Mobilizing to Save Civilization.
Andrew C. Revkin posts an exchange between Vaclav Smil, the University of Manitoba analyst, and Lester Brown, president of the Earth Policy Institute in the New York Times Dot Earth blog. Posted January 10, 2011.