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Climate change and energy

These deep-sea “potatoes” could be the future of mining for renewable energy

Battery materials dot the ocean floor. Should we go get them?

manganese nodules in the Clarion Clipperton Fracture Zone seabed
Polymetallic nodules contain nickel, cobalt, and other key battery ingredients.ROV KIEL 6000, GEOMAR via Wikipedia

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I’ve been on the road this week, and by a stroke of luck I got to visit one of my favorite places in the world: the whale shark exhibit at the Georgia Aquarium in Atlanta. 

The tank is massive, holding over 6 million gallons of water. Six full-sized whale sharks swim around it, along with lots of manta rays and other assorted ocean creatures. I remember sitting down in front of the main viewing window on a school field trip, captivated by this gigantic array of life. But compared with the ocean, even this huge display is infinitesimal—less than a drop in the bucket. 

I’ve been thinking a lot about the oceans recently, even before this aquarium trip, because there’s been growing buzz in the news about mining in the deep ocean. 

Proponents say certain spots on the ocean floor could be a key source of some of the metals we need to build batteries and other technology that’s crucial for addressing climate change. But whether commercial efforts should go ahead is a source of growing controversy: there’s a lot of uncertainty about how they might affect ecosystems, and a lot of politics at play. 

A UN group just finished up meetings last week to try to sort all this out, and there could be some key actions on deep-sea mining this summer that you should know about. So this week, let’s talk about mining and the ocean. 

Why mine in the ocean?

To transform our world to address climate change, we need a lot of stuff: lithium for batteries, rare-earth elements like neodymium and dysprosium for wind turbines, copper for, well, basically everything. 

We’re not exactly going to run out of any of these key materials: the planet has plenty of the resources we need to build clean energy infrastructure. But mining is a huge and complicated undertaking, so the question is whether we can access what we need quickly and cheaply enough. 

Take copper, for example. Demand for the metal in energy technologies alone will add up to over a million tons every year by around 2050, and it’s getting harder to find good spots to dig up more. Companies are resorting to mining sites with lower concentrations of copper because we’ve exhausted the accessible higher-concentration spots we know about. 

The ocean could be a new source for copper and other crucial materials. Seabed mining could happen in a few different ways, but the stars of the show are potato-sized lumps called polymetallic nodules. These nodules dot the ocean floor in some places, especially in the Clarion-Clipperton Zone, which lies between Hawaii and Mexico in the Pacific Ocean. 

Nodules form naturally over millions of years as trace elements in seawater get deposited onto small objects nestled together on the ocean floor, like bone fragments or shark teeth, and slowly grow. They contain manganese, cobalt, copper, and nickel, which are all used in the lithium-ion batteries that power electric vehicles today, as well as a bit of iron and titanium and trace amounts of rare-earth metals and lithium. 

Because of the impressive array of metals they contain, at least one company has likened each nodule to a battery in a rock. That’s why over the past decade, companies have begun to explore the possibility of commercial mining operations in the deep sea, mostly in the Clarion-Clipperton Zone. 

But not everyone is on board with this use of the ocean, because a lot of life is found in and around these nodule fields, from corals and sea cucumbers, to worms and dumbo octopuses, not to mention all the tiny creatures we haven’t discovered yet. Scientists have also raised questions about what will happen when the mining operations kick up sediment: plumes could disturb wildlife or even the natural carbon storage beneath the seabed. 

Who gets to decide? 

Governing international waters is a complicated business. For deep-sea mining, there’s a UN group in charge, called the International Seabed Authority (ISA), which was founded in 1994 and is based in Jamaica. The ISA has been developing a mining code for commercial operations, but some companies want to get things going already. 

A process is in place to address this situation, called the two-year rule: at any time before regulations get passed, a member nation has the authority to give the ISA notice that it wants to start mining, and the ISA then has two years to come up with rules. 

The small island nation of Nauru, in Micronesia, triggered the two-year rule just about two years ago, so the deadline is July 9, 2023. But the ISA’s next meeting, during which it could potentially finish up regulations, starts July 10, so that deadline is toast. 

It’s not totally clear exactly what will happen after the deadline passes. One possibility is that a company could submit an application to begin commercial mining anyway, which the ISA might choose to review even if the rules aren’t established yet. 

A subgroup of the ISA just wrapped up two weeks of meetings in Jamaica, where delegates discussed potential regulations and how the group would handle commercial mining efforts in the meantime. As Bloomberg reported, there are growing calls from both member nations and advocacy groups for the ISA to not consider applications until the rules are done. Others are calling for either a temporary pause or outright ban on any commercial ocean mining until more research is available about its effects on the ocean. 

Weighing the potential benefits and harms of deep-sea mining, especially compared with land-based mining, is a complex undertaking. This is definitely an ongoing story, and one you’ll be hearing more about from me. For now, I’d recommend checking out this episode of How to Save a Planet from last year and this piece about the ecosystems at stake from the New York Times

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