If we use up all the fossil fuel what's going to happen to the land mass where the fuel existed?

Answer 1

If we use all the resources then the land mass where the reources existed will become fuel-resource deficient or empty fuel resources.

Answer 2

If all fossil fuels were depleted, the land where they existed would likely experience changes in geology and ecosystems. Oil and gas reserves are often in underground deposits, so extraction can cause subsidence or sinkholes. The land could also see ecological shifts as habitats adapt to the absence of fossil fuel extraction activities.