Could we breed trees which capture more CO2? We increased crop yields multifold already: https://ourworldindata.org/crop-yields So maybe we can do the same to carbon yield? Are trees the plants which capture most CO2 per hectare?
There's part of me thinks just let the worst happen and let it end half of humanity, that way we might learn to live more in harmony with our environment. Currently we're a pox on this planet.
You do realize that would be mostly the half whose nations had nothing to with this mess in the first place, right? The rich well of nations of northern hemisphere will not suffer dramatic population falls (just the slow, endemic kind from low birth rate).