I think the going to AGW hell has better odds.
I wonder at times when I am in the patch & can see the mess first hand, if half the planet was doing without food & water due to the pollution, would we even so much as slow down. Honest answer would be no, as long as we were not that half of the planet. Sucks but that's it at the moment.
AGW is a problem, but folks that are only driving their recycling to the station and buying some veggies at a farmers market are not going to solve it.
Re your observation on human nature, I def see your point, but on a good day I think that over time (a decade, a generation?) such as system would not prevail. If AGW models are correct, then CO2 pollution induced drought might cause us to try your thought experiment.