Most of non-free regimes are based on the income from natural resources, especially from fossil fuels: Venezuela, Iran, Russia, North Korea etc. Additionally, some other non-free regimes are maintained by these ‘donors’: Belarus, Tajikistan etc.
Among other purposes, they use money on wars.
If (at least) the free countries go green, most of the oppressive regimes will be left without money. No money for force, no money to enslave others. Have to change.
That’s it. Go green.
Freedom in the World 2019 Map is from: https://freedomhouse.org/report/freedom-world/freedom-world-2019/map