They won’t. There are bacteria that eat plastic. There is no path* to creating oil or coal again, biology is too good at breaking hydrocarbon precursors
If enough greenhouse gasses get released by this breakdown of hydrocarbons, and the temperature rises enough, the oceans may stop circulating and loose all their oxygen. The resulting die off and anoxic environment might be enough to form a massive new layer of tar and proto-oil with some luck.
They won’t. There are bacteria that eat plastic. There is no path* to creating oil or coal again, biology is too good at breaking hydrocarbon precursors
*Except by deliberate human industry
If enough greenhouse gasses get released by this breakdown of hydrocarbons, and the temperature rises enough, the oceans may stop circulating and loose all their oxygen. The resulting die off and anoxic environment might be enough to form a massive new layer of tar and proto-oil with some luck.