Climate change is the mother of all negative externalities .

气候变化正是所有负外部性的源头。

Are you worried at all about externalities we won 't or can 't anticipate ?

您是否会担心那些我们没有或者无法考虑到的外部问题？

There 's no way to attack the problem without taking a global look at externalities .

如果不以全球视角来看待这个外部成本，那么根本没有办法触及这个问题。

But I am not sure you have correctly identified the positive and negative externalities here .

但我不确定，在这个问题上，你对正外部性或负外部性的判断是否正确。

It is possible to eat a lot of fatty food , exercise frequently and not generate any externalities .

如果食用大量的垃圾食品，但经常锻炼，那么可能并不会产生任何外部效应。