Yes, that is what I meant by the "This has practical problems.." part. CO₂ emissions is the extreme case of this difficulty. Almost everyone contributes a tiny

Yes, that is what I meant by the "This has practical problems.." part. CO₂ emissions is the extreme case of this difficulty. Almost everyone contributes a tiny part to the problem, and almost everyone is also a potential victim of it. Because of that, I'm not categorically opposed to regulation handling these difficult situations. But I also note that airplane fuel IS regulated, and that has NOT solved the problem! The best solution to CO₂ emissions is some form of carbon tax, but that has proven politically impossible in most jurisdictions.