Seems like they’d have to be counted multiple times between the oil company investors, the airline investors, and the passengers, etc. Disclaimer though I haven’t read the article, but I am curious how they do the accounting.
Edit: or are they considering the entity that owns the fuel that’s being burned? But the whole issue is that the carbon is an externality of other economic processes. I could offer to accept ownership of all carbon emitted by any company for a nominal fee and become the world’s only polluter according to that methodology.