Seas At Risk argues for the importance of rethinking energy consumption in a no-mining scenario, as well as for careful environmental policy. Without a clear vision, controversial biofuel production might make up the energy shortfall, with vast areas of land given over to forestry practices to provide wood as a source of building materials, energy and biofuels.
But the work wouldn’t stop there. For Lèbre, who researches mine closure, the closed mines themselves would be a huge source of concern. If all mining stopped there would still be an area at least the size of Austria with degrading and in some cases dangerous levels of heavy metals. “Mining is a process of entropy. We are bringing material from locked-up concentrations underground and letting them out into the world.”
Ensuring the clean-up and and rehabilitation of these areas would be vital. Mines usually operate at depths below the water table, which need to be constantly dewatered using pumps. When a mine is abandoned, the ground water gradually refloods underground passages and mineral seams over many months, creating acidic reservoirs of water. Above ground, meanwhile, tailings ponds and piles of low-grade ore with traces of heavy metals lie in wait. “All of this material is exposed to water and oxygen,” says Lèbre. Exposing such elements to, well, the elements, wreaks havoc on ecosystems, soils and water supplies through acid leaching. “A mine that is abandoned can have chronic pollution for hundreds if not thousands of years,” says Lèbre.
Cleaning up a mine consists of reducing water acidity, detoxifying the soil and treating waste before reintroducing flora and fauna to the site. It’s a long, expensive process and can cost billions for a single, large mine. Avoiding an environmental catastrophe, and cleaning all the world’s mines at once, would cost hundreds of billions or even trillions.