Why cherry-pick per-capita when what matters to the climate is actual output, not output per capita. Lets take Australia, as an example, their total co2 output is around 1% of the world's co2 output. If Australia ceased producing all of its co2, it wouldn't make much difference at all. Per capita figures are just a waste of everyone's time.
As someone from a smallish country (UK), I don't think I agree. Per capita is the only-) way of measuring emmissions that doesn't wind up a proxy for just listing the biggest countries.
Almost 1/5 people are in China, if tomorrow the country divided itself up into smaller nations would thay change anything about the pollution bring emmited?
I always try to convince people the best metric is CO2/land area. It actually adjusts for the size of your country without the silly idea that having more people means your country is doing "better" from an emissions perspective.
Great, let's just move everyone to Australia! Or wait...
Unless you have policy recommendations to change the total number of people on Earth (please don't) then global emissions per capita are the only stat that matters.
Per-capita is a hint to the capacity of reduction or a measurement of the inefficiencies of a country.