Key word - leverage
Methane may be a more effective greenhouse gas, but if increasing atmospheric CO2 raises the temperature a little, which causes permafrost melting, which generates methane, which raises the temperature a *lot*. Where is the point in that chain where humans have (or maybe *had*) leverage on the whole phenomenon?
Due only partly to politically-motivated nay-saying, we may be well past the point where that leverage can do anything.
And wholesale moving of populations? Wow, talk about expensive and disruptive. Shall we move all of the Southeast Asians to your neighborhood?
I will take the Pacific Islanders.
Any volunteers for the Southern Europeans (yes Europe) where the climate may no longer be able to support even subsistence agriculture?
Oh yes, and Africa?.....
All maybe not in my lifetime, but surely in my kids'.