加拿大油砂中沥青总含量达4000亿立方米，是世界最大的沥青资源。按现有技术，阿尔伯塔的油砂中储藏有原油1800亿桶，随着技术改进和油价上涨，未来有望多提炼出1300亿桶石油。

"Iowa is going to be affected more by the tariffs than a lot of states because so much of our economy is dependent on agriculture, and so much of agriculture is dependent on exports," said Charles ...