I mean, if every ton of CO2 emitted had to be offset by certificates for 1.1 tons of CO2, that were truly removed from the atmosphere, the climate problem would be solved over time and we could switch to 1:1 once we got the atmosphere back to pre-industrial levels. While this would surely reduce quality of living, I would be surprised if this meant that only 500k people per continent could survive. Surely, we could do better.