Covering this drop in reserves – more than half of gas reserves and a fifth of oil reserves have been consumed – with imports implies an annual cost of more than $300 billion. Indeed, after two decades of cheap, abundant energy and exports of surplus output, a new cycle of expensive, scarce, and imported energy has begun, as oil production has fallen by one-third since 1998, and gas production by 15% since 2004.
用进口弥补储量的下降——大约一半的天然气储量和五分之一石油储量已经被用掉了——意味着每年要花去3000亿美元以上的成本。事实上，在经历了20年廉价充足的能源供应（甚至还有余量可供出口），新的昂贵、稀缺、进口能源周期已经开始。石油产量自1998年以来下降了三分之一，天然气产量自2004年以来下降了15%。