Earth's recent climate spiral.

[Leonardo17]

Nope, it should come from countries that can afford it with developing nations contributing what they can. The idea of basing it solely on the proportion of CO2  is silly. Especially when you consider that rich countries benefit from the economic activity that produces that CO2.

It's unfair, poor countries should pay for environmental damage they caused

There will be no "unfair" if we are no longer here