Posted July 28, 2013, 9:37 p.m. ET
Scientists in Japan and the U.S. say they are moving closer to tapping a new source of energy: methane hydrate, a crystalline form of natural gas found in Arctic permafrost and at the bottom of oceans.
At room temperature the crystal gives off intense heat, earning it the nickname of "fire in ice," and making the estimated 700,000 trillion cubic feet of the substance scattered around the world a potentially major fuel source, containing more energy than all previously discovered oil and gas combined, according to researchers at the U.S. Geological Survey.
Commercial production of methane hydrate is expected to take at least a decade ...