> the issue is the total emissions under the control of any one government
Total emissions definitely matter (no need to give speeches in Palau even if per-capita emissions are much greater than in the USA), but considering this number without regard to the population size is completely unrealistic and insensitive.
For China's overall emissions to get to the same level as the USA, that means a Chinese citizen would be expected, on average, to emit less than half of what a US citizen emits.
Would you expect a Chinese citizen to only eat half of what a US citizen eats, just because there are more people in their country ? Of course not.
China's trend is dramatically upwards because a big chunk of the population is still getting out of poverty. Of course CO2 emissions are increasing.