The point of the country splitting hypothetical was to show that a country's total emission is not a useful measure of whether they are doing better or worse than any other given country on addressing emissions.
A useful measure should not be affected by where we happen to draw political boundaries on our maps.
If you ignore that countries really do exist and really do produce those emissions in order to succeed in their economic objectives, sure, then it's not useful.
Outside that thought experiment it actually is useful, and that's why we have data showing that China leads, by far, in producing emissions. By the way, they lead in methane and nitrous oxide as well -- it isn't just carbon dioxide.
https://ourworldindata.org/greenhouse-gas-emissions
It is not useful because it ignores population.
One property a useful measure of something undesirable (like CO2 emissions) should have is that if you identify the country that is doing the worst by that measure, and they were to change so that their economy works like that of the second worst country and their people live a lifestyle nearly identical to the people of the second country, that should improve the thing being measured.
Total by country fails at that. If China were to change so that they are basically a clone of the US economy and lifestyle their emissions would go way up.
Conversely, if the US were to change to be a China clone that would result in a big decrease in total emissions.
No, the description of what actually is produced, and by who, is accurate and useful.
If you want to suppose those these two countries' populations changed lifestyles, I can also entertain that argument. You'd want to consider the economic reasons why one produces the emissions it does right now, and then suppose how that changes. In such a case, who is purchasing China's manufacturing output, and who is now purchasing that of the US?
Ignoring the world's largest and fastest-growing source of emissions simply because its per-capita rate is lower is a distraction from solving the actual problem.
It's an enticing "what if," but does not reflect the reality of the real data we have today. That data says China is the biggest emitter of greenhouse gases.
If it is faster growing as a consequence of greater population growth, then that seems like maybe a point.
Now, yes, if we consider just China, then that being a major contributor to world CO2 emissions does imply that if we are to have total emissions under some total global rate, then, well, the total emissions from China need to be below that rate, certainly.
However, it seems a hard ask to try to get China to put stricter per-capita limitations on themselves than we are willing to endure ourselves?
Now, if the higher population places reduced their emissions and the lower population places stayed the same, that might be sufficient, but it also seems a bit, free-riding for those lower population areas?
Also, yeah the consumption of the goods produced seems pretty relevant.
> However, it seems a hard ask to try to get China to put stricter per-capita limitations on themselves than we are willing to endure ourselves?
It is especially a hard ask when you consider that because of the longevity of CO2 in the atmosphere there is more US/Europe CO2 in the atmosphere currently than there is Chinese CO2.
The US and Europe spent well over 100 years massively emitting in order to build up the levels of prosperity they now enjoy. If everyone else that wants prosperity tries to follow that same path it will be disastrous.
The only way to give every country a chance to reach a decent level of prosperity without using a a disastrous amount of fossil fuels is for (1) countries that achieve prosperity to rapidly and drastically cut their emission by switching to renewable energy, and (2) the prosperous countries provide subsidies for renewables to the countries that are trying to become prosperous so many of the latter can skip much of the "fossil fuel our way to prosperity" phase and go more directly to the prosperous renewal energy powered country endgame.
> Also, yeah the consumption of the goods produced seems pretty relevant.
In a fair system it is relevant, but as an adjustment after population. A fair system would start with the amount of total annual emissions that we decide (somehow) we need to keep under as a world, divide that by the number of people, and then assign each country that quotient times there population as their annual emission allowance.
If a country emits more than that they would have to get some other country to give them some of that country's emission allowance. That could be incorporated into international trade by making it so outsourcing production of something to another country requires you to provide that other country with enough of your emission allowance to cover the making of that thing.