So if China were to spin off each province as a separate country and the US were to spin of each state as a separate country with each of the new countries emitting exactly as much CO2 as it had before it was a separate country, this would be an improvement?
If we go by per capita, the country that contribute the most to the world pollution is a island country with 300 islands and 1700 people. At the same time there are a bunch of oil countries which list as the most green countries in the world because per capita they got close to nothing in pollution per person. If we go outside of countries, the international space station and antarctic would have insane amount of CO2 per capita since only a very small number of highly specialized people living there.
If we want to stop climate change, going to Palau and Luxembourg with remedies will have zero impact. Their numbers at top of the table is only relevant in terms of statistics.
If one is to ask "whom's individual citizen way of living is contributing most" we would look at per capita C02. If the question is "Who is at risk of increasing their pollution" you would look at living standards and growth rates. If you ask "Who has the beast means to invest into climate change preventing technology" you would look at GDP. If you ask "where in the production chain pollution is created" then looking at trade gives that. If the question is whom is to be blamed historically for getting us into this situation then the historical global cumulative CO2 graph shows that, through I am a bit skeptical that it actually gives a correct picture since ww1 and ww2 were very central in ushering us into the age of fossil fuels.