You are correct that per capita doesn't matter to the global climate but it's only relevant because regulations are enforced on a nation-based fashion.
As a Chinese national living in the U.S., I would like my fellow countryperson to have the same standard of living as an average American does. Unfortunately this view is not shared by many Americans, including Obama [0].
[0] "...if over a billion Chinese citizens have the same living patterns as Australians and Americans do right now then all of us are in for a very miserable time, the planet just can't sustain it": https://www.abc.net.au/7.30/face-to-face-with-obama/2673356
As a Chinese national living in the U.S., I would like my fellow countryperson to have the same standard of living as an average American does. Unfortunately this view is not shared by many Americans, including Obama [0].
[0] "...if over a billion Chinese citizens have the same living patterns as Australians and Americans do right now then all of us are in for a very miserable time, the planet just can't sustain it": https://www.abc.net.au/7.30/face-to-face-with-obama/2673356