I think the point is that unless we can make a good case that some people have some sort of natural or divine right to a bigger share of the world's total CO2 e

I think the point is that unless we can make a good case that some people have some sort of natural or divine right to a bigger share of the world's total CO2 emissions budget then other do, we have a lot of countries that are over budget. It's hard to tell the poorer countries that they should stay poor so as to keep the world under budget, but using fossil fuels for many of them is the only to become not poor in a reasonable timeframe with their existing resources. Just considering the welfare of their own citizens and their own resources their best path will often be a rapid increase in fossil fuels to get to a reasonable level of wealth and then start emphasizing renewables. Since it is unlikely that the existing wealthy countries can reduce emissions enough to keep the world under budget as the developing countries follow the aforementioned path, we probably need the wealthy countries to help out the poorer countries to try to speed things up so they go through the fossil fuel phase faster.