> Oil exists in the ground. I don't see an issue with pumping it up, using it for a bit, and putting it back into the ground via a landfill.

- The form it is put "back into the ground" isn't the same form it was "pumped up".

- The landfill isn't the same location where we put it compared to where we sourced it (much deeper).

I'm not an ecologist, but both these differences have complex consequences for earth and us.