I really wish I were intelligent enough to systematize it, but billions of dollars have so far failed to establish procedures for sound reasoning. Or maybe just make those procedures commonplace.

The national based calculations hide the global chain of events and the interconnectedness of their economies through marketplaces.

It's a much harder calculation to figure out who's to "blame" for say, the cost of an electronics device that uses a dozen countries to manufacture or say even a food that is sourced in one country, processed in another, packaged in yet another, and then consumed in a fourth...

Do we assign everything to the point of consumption? That's not fair either. Distribute it over each?

That's what we currently do but it problematically hides the relationship. The British are still consuming textiles, they just aren't domestically manufacturing them. They may even still own the plants, they're just in, likely, Bangladesh which is seeing a ~5% annual CO2 increase.

That should matter if those things were made by the demand of British consumers but in our traditional models it doesn't go into Britain's bucket.

That makes it an accounting trick with no clear way to resolve it.

It would be like graphing the number of backyard burials for a culture that moved from the practice of backyard burials to cemeteries and mistaking it as if they somehow vanquished death and are now eternal except in a few very deadly places. We've moved towards globally centralized manufacturing.

There's lots of citations that can be made but the way things work are way different now then say in 1960.