Rich in precious minerals, the ocean floor may soon be opened to deep-sea mining — but at what cost?
What's down there?
A trove of metals and minerals needed for the green revolution — to make electric vehicle batteries, solar panels, wind turbines — and for electronic devices such as cellphones. These elements, including nickel, cobalt, copper, and manganese, are highly sought after among energy and manufacturing companies, and they abound on the deep-ocean floor near geothermal vents and in the crusts of underwater mountains. The most promising source, though, is the lumpy, potato-shaped rocks called polymetallic nodules. Formed over millions of years by minerals building up on objects such as shell fragments or shark teeth, the nodules are thought to contain far more rare-earth elements than exist on all landmasses. The Clarion-Clipperton Zone (CCZ), a swath of the Pacific between Mexico and Hawaii that's about the size of the U.S., is estimated to hold over 21 billion metric tons of nodules, potentially worth trillions of dollars. "We need those metals," said Peter Tom Jones, head of Belgium's KU Leuven Institute of Sustainable Metals and Minerals, "to make the transition to a less destructive system no longer based on fossil fuels."
How would they be mined?
The process is fairly simple. A support ship sends down a robotic harvester that scrapes the top 5 inches of ocean floor and hoovers up the nodules. The rocks are then cleaned of sediment, which is piped back into the ocean deep below the surface. So far, there have only been a few exploratory forays — including one by the Vancouver-based mining concern The Metals Company in 2022 that extracted more than 3,000 tons of nodules in just two months. Several countries, including Japan, South Korea, and Norway, have launched national programs to get ready to mine in their own coastal waters. But while most of the deposits lie in international waters, there are no international regulations yet in place, thanks partly to intense opposition from environmentalists.
What's the objection?
Critics say the mining process would irreversibly harm delicate underwater ecosystems untouched for millions of years. The nodule beds abound with life, including sea worms, crustaceans, sponges, and corals, as well as many species not yet known to science. A study last year found 5,000 new species just in the seabed of the CCZ. In addition to destroying their immediate habitat, mining would send up great plumes of silt that could spread widely, smothering sea creatures further away. It would also disturb ocean-floor microbes that consume carbon dioxide, possibly lessening the ocean's ability to capture and hold carbon long-term. Seabed ecosystems "take millennia to establish and can take seconds to destroy," said Australian marine scientist Tony Worby. "We're playing with fire to think we can go down to the deep sea and strip-mine it without massive repercussions."
Who decides?
Under the 1994 U.N. Convention on the Law of the Sea, nations can freely exploit resources within 200 nautical miles of their own shores. Beyond that, though, jurisdiction falls to the International Seabed Authority, a U.N.-affiliated intergovernmental body with 168 member nations — not including the U.S. The ISA has issued about 30 permits to nations and contractors like The Metals Company to do exploratory mining in the CCZ and three other areas. It was due last July to issue regulations laying out whether and how deep-sea mining can proceed. But it missed the deadline, and now says the regulations — which will set ground rules for allowable noise, sediment disturbance, and other factors — may not be completed until next year. In the meantime, organized opposition to deep-sea mining is building.
Who opposes it?
Last year, in the wake of a U.N. report that concluded the mining would be "highly damaging to ocean ecosystems," 24 countries called for a moratorium until the environmental impacts are better understood, among them Britain, Spain, New Zealand, Canada, Ecuador, and Costa Rica. The Deep Sea Conservation Coalition, which encompasses more than 100 environmental groups, is fighting to stop undersea mining altogether. It argues that advances in battery technology as well as new techniques for recycling battery elements will soon cut down on the demand for newly mined metals. And tech giants Samsung and Google have backed a moratorium, while automakers such as BMW, Volvo, and Volkswagen have pledged not to use materials sourced from the sea.
What is the argument for doing it?
That the metals are vital to wean the world off fossil fuels. Demand for nickel is expected to increase 20-fold by 2040, manganese eightfold. If these elements don't come from the ocean, they will be mined on land, which could be even more destructive. Land mining often causes displacement of indigenous communities and grievous ecological harm. Currently, the world's top nickel producer is Indonesia, which is clearing its rainforest in pursuit of more. Turning to the sea would be far less damaging, say proponents. It could also allow other countries to break into a rare-earths industry that has so far been dominated by China and Russia. "We're not talking about mining all of the ocean. We're talking about one little patch," said The Metals Company CEO Gerard Barron. "If not this, then what?"
The U.S. gets left behind
The U.S. has no voice on the ISA as it crafts mining rules — and can't be awarded exploration permits or mining licenses if and when they are granted. That's because the Senate never ratified the 1982 Law of the Sea treaty that laid the foundation for the agency. Though Washington was key to negotiating the treaty, President Reagan declined to sign, saying it could undermine U.S. sovereignty on the high seas. Since then, conservative Republicans have remained opposed, and a 2012 push to ratify backed by both business and environmental groups failed after the Heritage Foundation fought it. Now, though, hundreds of former political, military, and security leaders are once again calling on the Senate to ratify the treaty. "With respect to deep-seabed mining," said former Republican national security official John Negroponte, China is "eating our lunch."
