Source: http://www.popsci.com/science/article/2010-03/china-and-us-race-burning-ice-fuel
Methane hydrate crystals show promise as a clean energy source
As explained in this comic, there's 85.4 trillion cubic feet of methane hydrate buried under Alaska. That's equivalent to 3 billion tons of oil, or enough to heat 100 million American homes for a decade. According to the Xinahu article, reserves of methane hydrate in China's Qinghai province are equal to 35 billion tons of oil, enough to supply China for 90 years.
Unfortunately, China lacks the capability to excavate the mineral. Even at an expedited pace, China's Ministry of Land and Resources estimates it could be 10 to 15 years before any hydrate-derived gas finds its way into Chinese homes.