Why not? You are assuming each country does basically the same stuff, rather than a divergent set of stuff they do best. If you drive people around in a car for a living, and I don't, it's palpably unfair to hold us to the same carbon budget. If you weren't driving me, I'd be driving you!
There is no reason the industry in one country should be exactly as carbon intensive as that in another, any more than the IT sector should be the same relative size, or the steelmaking sector should be the same.
