Similarly, oil and natural gas were to run out in 1990 and 1992, respectively; today, reserves of both are larger than they were in 1970, although we consume dramatically more. Within the past six years, shale gas alone has doubled potential gas resources in the United States and halved the price.
类似地，石油和天然气原本预计将分别于1990和1992年耗尽；如今，两者的储备均高于1970年水平，尽管我们的消费量大大地增加了。在过去六年中，页岩气一项就把美国潜在天然气资源量扩大了一倍，价格削去了一半。