@whitequark so the value judgement they're making there would be that if business class wasn't there then you could move more people per flight, thus making it more carbon efficient. I don't know if that's the *best* way to think about it, but it is one way.

@gsuberland right, but as far as i know airlines barely (if at all) break even on economy class seats, so it's just as easy to argue that if business class seats weren't there we'd just see fewer flights. (which would probably be even more carbon efficient?)