Supported byAbout this contentSun 29 Aug 2021 10.00 BSTIn a display cabinet in the recently opened Our Broken Planet exhibition in London’s Natural History Museum, curators have placed a small nugget of dark material covered with faint indentations. The blackened lump could easily be mistaken for coal. Its true nature is much more intriguing, however.The nugget is a polymetallic nodule and oceanographers have discovered trillions of them litter Earth’s ocean floors. Each is rich in manganese, nickel, cobalt and copper, some of the most important ingredients for making the electric cars, wind turbines and solar panels that we need to replace the carbon-emitting lorries, power plants and factories now wrecking our climate.These metallic morsels could therefore help humanity save itself from the ravages of global warming, argue mining companies who say their extraction should be rated an international priority. By dredging up nodules from the deep we can slow the scorching of our planet’s ravaged surface.“We desperately need substantial amounts of manganese, nickel, cobalt and copper to build electric cars and power plants,” says Hans Smit, chief executive of Florida’s Oceans Minerals, which has announced plans to mine for nodules. “We cannot increase land supplies of these metals without having a significant environmental impact. The only alternative lies in the ocean.”Other researchers disagree – vehemently. They say mining deep-sea nodules would be catastrophic for our already stressed, plastic-ridden, overheated oceans. Delicate, long-living denizens of the deep – polychaete worms, sea cucumbers, corals and squid – would be obliterated by dredging. At the same time, plumes of sediments, laced with toxic metals, would be sent spiralling upwards to poison marine food-chains.“It is hard to imagine how seabed mines could feasibly operate without devastating species and ecosystems,” says UK marine biologist Helen Scales – a view shared by David Attenborough, who has called for a moratorium on all deep-sea mining plans. “Mining means destruction and in this case it means the destruction of an ecosystem about which we know pathetically little,” he says.It is a highly polarised dispute. On one side, proponents of nodule extraction claim it could save the world, while opponents warn it could unleash fresh ecological mayhem. For better or worse, these mineral spheres are going to play a critical role in determining our future – either by extricating us from our current ecological woes or by triggering even more calamitous outcomes.

Source: Is deep-sea mining a cure for the climate crisis or a curse? | Mining | The Guardian