"Why is it that natural gas sells in the U.S. for $3.94 per 1,000 cubic feet and in Europe and Japan for $11.60 and $17, respectively? Part of the answer is our huge supply. With high-tech methods of extraction and with discovery of vast gas-rich shale deposits, estimated reserves are about 2.4 quadrillion cubic feet. That translates into more than a 100-year supply of natural gas at current usage rates. What partially explains the high European and Japanese prices is the fact that global natural gas markets are not integrated. Washington has stringent export restrictions on natural gas."