As for coal, at current rates of consumption the world has enough deposits to last for 114 years. But as oil and gas are depleted, the speed at which coal is used up seems sure to increase. Can anyone guarantee that in two centuries 'time, our grandchildren will not have to live in a primitive age without cars or electricity?
即使煤礦儲量還能讓人類再使用兩百一十四年，但石油等主要能源相繼耗盡後，煤耗量勢必相對增加，任誰也難保證，兩百年後，我們的子孫是否得被迫生活在無車、無電的原始時代？