That's not the problem: a Nigerian emits 5% of the carbon footprint of a US person. So they could have 20x as many babies as the Americans? We also have wide differences in the same town and family, too: for instance, my father has emitted at least 20x the CO2 than I did in 2020 (because he like big cars, big houses and fly many times a year).
The problem is clearly what each human being can emit for themselves, according to their means.
The problem is clearly what each human being can emit for themselves, according to their means.