Clearly, if I did nothing more, but I took every car, doubled its fuel economy, its emissions would go to 50% of what they are now, no other changes being made.

显然，如果我什么也不做，但是我把没量车的汽油价加倍，汽车废气排放量就会是现在的一半了，别的不会有什么改变。

麻省理工公开课 - 固态化学导论课程节选