How much nonrenewable energy is left?

Answer 1

There is actually quite a lot of non-renewable energy left.

Even ignoring all the fossil fuels (stored sunshine), there are still all the nuclear fuels, some of which are not even touched yet.

The Nuclear Fuels industry at present has been based entirely on the desire to recover Plutonium for the manufacture of Atomic Weapons. That is why the construction of new atomic plants was essentially stopped - the governments have enough plutonium for an overkill of bombs, and the problems of disposing of the waste products is difficult.

And, even if we had run out of Uranium - a possibility - there is still the possibility of generating nuclear power using Thorium, of which we have huge resources. I think India is the only country looking at Thorium.

There is also the Geothermal heat of the Earth in its various forms.

And solar power. And tidal power.

So we are OK for sources of power in the foreseeable future.

But perhaps there is a temporary problem in the supply of liquid fuels. But this may be overcome by using biofuels - more sunshine.