As a curiosity, I saw a few years ago an article from Africa: 'Meet the Ugandan Businessman with 13 Wives, 176 Children'. I hope we can agree that this kind of reproductive behavior is utterly unsustainable in a world that has learned about its limits (and sadly overshot them already).
https://face2faceafrica.com/article/mustafa-mugambo-mutone
Edit: Of course landmass is an approximation. Of course Alaska / Arizona are not Iowa. On the flip side, Tibet / Xianjiang are not Guangdong either. The core point that given that TotalEmissions = Population * PerCapitaEmissions and the Earth only cares about TotalEmissions. We've got to price for the Population term somehow, lest it becomes an unaccounted externality.