[PeanutCurry]

I've presented this from the perspective of the U.S. but I think the same position could be argued for a lot of countries. Further, India and China are doing better in terms of pollution per capita as you've pointed out. However, the counterargument would be that both natiuons' populations are the result of their own domestic policies. There's no reason for other countries that have successfully managed to restrain their own potentially explosive population growth via domestic policy to give China and India a pass because of raw numbers. If China and India are concerned about the difficulty of regulating their nations' pollution in lieu of their massive populations that shouldn't be everyone else's problem. If they want to make trade agreements based on their pollution output that's one thing. But arguing that looking at raw output is unfair because of their per capita output ignores decades of irresponsible population management on their part.

[azernik]

The US and Europe have not "restrained" explosive population growth; they just had it in the 19th and early 20th centuries instead of in the late 20th and early 21st centuries. The European population as a percentage of the world's population, for example, peaked around the first third of the 20th century. The UK population multiplied by 7 to 10 from 1800 to today; the German population in more or less its 1914 borders multiplied by 3 between 1834 and 1914 (I don't have a comparable census going earlier); and US population from 1790 (first census) to 1830 (when immigration became more of a factor and confuses the picture) tripled. Note that for Germany and the US I'm restricting myself to subsets of the demographic transition period; in most modern developing countries this process has been compressed into about 50 years.

See [https://en.wikipedia.org/wiki/Demographic_transition] for more on this (damned near universal) phenomenon.

[PeanutCurry]

That doesn't really address the core of my argument though, which was that poor policy for mitigating explosive population growth led to China and India have such wildly population sizes compared to other nations. To put this in perspective, the world has 7.5 billion people roughly, China and India account for 2.6 billion of that figure. I don't see a hard reason for why other nations should seriously consider per capita emissions a fair metric for designating responsibility when China and India gain such a strong advantage from that metric compared to similarly developed nations. It seems like there's very little reason why any nation besides China and India would consider that economically fair.

I appreciate your point that other nations have also experienced explosive population growth. However, it's hard to find that persuasive when the end result is two countries having over a third of the world's total population. Especially when neither of those countries are ones that you cited as having had their explosive growth before the rest of the world. It's difficult for to see that as something that happens with responsible domestic policy.

[azernik]

Yes it does. You think China having 1/6 of the world's population is just a factor of modern policy? That's probably (estimates are fairly fuzzy) lower than its proportion of the world population in 1600. See e.g. [1] which estimates world population in 1600 in a band centered at 550m, with estimated populations of late-Ming-dynasty China around 160m.

You seem to view the mid-19th to early-20th centuries, when Europe temporarily had about 1/3 of the world's population because it went into its demographic transition so early, as a good baseline. It is not.

The reason I mentioned Europe having gone into its explosive growth so early is that it was so early that it affects your assumptions, such as that Britain "should" have a quarter instead of a twentieth of the population of China.

[1] https://www.census.gov/population/international/data/worldpo...