Sounds like communism!

We all have an interest in overproducing crops. If, say, Florida becomes an aquarium, or there's a disease that wipes out a lot of a particular monoculture, we don't want a ridiculous spike in food prices (or worse).

Is a lack of tax really a subsidy?

I would think most of the subsidies are governments paying companies to extract it locally rather than import it from a cheaper country, so the country is less exposed to world events.

Where a non-subsidy version of this would be to tax the bollocks off any foreign imported fuels so it makes more sense to extract it locally.

Of course the reality is that most countries need both locally extracted and imported fuel to meet demand, and that you, the taxpayer, will be picking up the bill in either case.

It would be better for everyone if we just left that shit in the ground where it belongs, but we ain't there yet.