If fossil fuel supply stopped tomorrow, 90% of the world’s population would likely starve to death within 2 years.
In 10 years, we wouldn’t be suffering famine any more and in 50 years we would back to the 1880’s.
Sooner than two years I suspect. I wouldn’t think anymore than six to eight months (given disease and poor health).
If just fossil fuels went, we would lose about 30%. If electricity went too, we’d lose 90%. And, more like 6-8 months.
I think it would look like one of those colonial worlds in the TV show Firefly - a few Big Bosses with ultra-modern technology and weapons controlling a large population of 1880's level serfs.
And you know how many of the elite are dreaming about just such a scenario.