How is this at all better ecologically, considering energy costs? The electrical demands to operate a mine are huge, most of which are used in pumping water out

How is this at all better ecologically, considering energy costs? The electrical demands to operate a mine are huge, most of which are used in pumping water out of the mine and air conditioning to make the atmosphere breathable. Air conditioning would arguably go up, since it is possible for plants to suffocate themselves with O2 in an enclosed environment. To me, this looks like a far worse ecological disaster than conventional farming unless we develop some form of truly free energy like practical fusion power.