I think if we were looking at this from a "pure economics" point of view, we'd say that the theory of externalities isn't wrong. But that 1. The UK just hasn't

I think if we were looking at this from a "pure economics" point of view, we'd say that the theory of externalities isn't wrong. But that 1. The UK just hasn't priced it high enough. 2. If the UK does not spend the money raised on ameliorating the externality worldwide, then they have not cancelled out the externality as they might claim to have.