AYESHA RASCOE, HOST:
Throughout the summer, NPR's Short Wave podcast has been bringing us the latest science from the depths of the ocean. And today, we travel to the sea floor, home to rare earth elements like cobalt, nickel and copper. These elements are used in everything from smartphones to electric cars to fighter jets.
WALTER SOGNNES: There is a reason why all countries and all nations - they have a critical minerals strategy. It's because the foundation for a green transition is all these different minerals.
RASCOE: That's Walter Sognnes, CEO of Glomar Minerals, a mining company based in the U.K. Companies like his and some countries, including the U.S., want to commercially mine the deep sea. But scientists are warning about the environmental impact. NPR's Emily Kwong has more.
EMILY KWONG, BYLINE: You may be wondering, why are there rare earth elements in the deep sea?
(SOUNDBITE OF SONG, "PART OF YOUR WORLD")
JODI BENSON: (As Ariel, singing) Look at this trove, treasures untold. How many wonders can one cavern hold?
KWONG: It's not because a little mermaid is down there hoarding treasure. Rather, rare earth elements accumulate over millions of years in these potato-sized lumps called polymetallic nodules found on the sea floor. Matthias Haeckel, a marine geochemist at GEOMAR Helmholtz Centre for Ocean Research Kiel in Germany, says these nodules are found in certain parts of the ocean and act as anchor points for all kinds of marine life.
MATTHIAS HAECKEL: I think the oldest nodule in the Pacific that has been dated was 14 million years old.
KWONG: In fact, the nodules grow at an average rate of tens of millimeters per million years through two main pathways - adsorption, which begins when a particle, like a fish bone or a shark tooth, falls to the ocean floor. And eventually, metals from the water column accumulate around that shark tooth, coating it with layers of metal. And the second way is diffusion. That's driven by microbes breaking down organic material.
Now, a lot of green technology is actually moving away from cobalt- and nickel-based batteries towards sodium-ion batteries or batteries made from renewable or recyclable material. But Sognnes maintains that the thirst for electric vehicles, wind turbines, weapons means that rare earth elements will have to come from somewhere and that the nodules in the ocean are a more reasonable place to get them.
SOGNNES: We believe that disturbance we are making in the ocean is a lesser effect than the mining in the rainforest, for instance.
KWONG: But what is the long-term damage to the ocean if these nodules are pulled up? Scientists have tried to predict that through experiments. One of the most significant is the European JPI Oceans project MiningImpact. A team led by Haeckel went to two places rich with nodules, the Clarion-Clipperton zone and the Peru Basin, where scientists in the '80s and '90s purposefully disturbed the sediment.
HAECKEL: To look how these experiment areas have evolved.
KWONG: Decades later, the sediment showed very little recovery.
HAECKEL: And the reason for that is that the energy flow into the deep sea is very low.
KWONG: Because less than 1% of marine snow or organic material falls into the deep sea, everything down there grows very, very slowly. So if mining were to ever happen and those nodules were removed, Haeckel says they would not come back any time soon.
HAECKEL: The specific fauna that needs these nodules for their life is gone permanently on our human timescales.
KWONG: These environments are fragile, and it's one of the reasons that 38 countries have called for a moratorium on deep-sea mining until scientists figure out the safest way to do it.
Emily Kwong, NPR News.
(SOUNDBITE OF SHIBUYA SCRAMBLE'S "MEET AT HACHIKO") Transcript provided by NPR, Copyright NPR.
NPR transcripts are created on a rush deadline by an NPR contractor. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.
