At present rate a minimum of 100-200 hundred years.. probably reaching 400-500 years if reutilization of weapons and secondary products of the nuclear cycle

Subtituting only coal would put the number at roughly 100 years minimum (more porobably 200-300).

Substituting also preent oil consumption in cars through electric would put it at less than 100 years, easily extendable until 100 years.

I think I remember the numbers correctly... but the numbers are indeed in the links.

A pleasure

I therefore claim to show, not how men think in myths, but how myths operate in men's minds without their being aware of the fact. Levi-Strauss, Claude