[captainmuon]

One way this could work is if we massively scale up renewables. While from a climate perspective you'd want energy to be as expensive as possible as long as there's fossil in the mix, from a social perspective you'd want it to be as cheap as possible. Ideally, all neccessities (power, food, water, transportation) could be made so cheap that everybody can afford them, and they cease to be commodities.

If you produce so much power - think solar on every rooftop, maybe one day fusion or clean fission becomes available - you will neccessarily have some way to store surplus energy. Especially with solar and wind. I can imagine that one way to do that will be synthetic fuel from air or from trash.

So yes, today it is not feasible (with today's technology and society). But I think it is not more unrealistic than other ideas popular around here, like hyperloop, fusion, or self-driving cars.