Deep Sea Mining May Be Necessary for a Greener Future – Twin Cities

Extracting cobalt, nickel, rare earth elements and other metals from the ocean depths could accelerate the world’s transition to renewable energy sources. These minerals are hard to come by on land, where mining also poses risks to communities and workers, but they can be found in abundance just above the ocean floor.

The problem is that the seabed is not a uniform environment, but has its own mountains and valleys and unique ecosystems, some of which are unexplored. The areas with all the minerals are among the most mysterious. They are also rich in strange life forms—lobster-sized shrimp and transparent fish that look like alien sea anemones and sea urchins that seem to gallop along the seabed.

One of the companies preparing to mine—The Metals Company, based in Canada—is funding research to explore a mineral-rich region called the Clarion-Clipperton Zone, a vast, elongated stretch of seafloor between Mexico and Hawaii, more than two miles below the surface of the Pacific Ocean. What these expeditions have uncovered is not just strange life but an entire strange system in which mineral-bearing rocks, which scientists call concretions, can generate some of the oxygen that animals inhabit the habitat breathe.

Deep-sea mining is sometimes portrayed as a story of greedy capitalists versus good scientists, but the reality is rarely so clear-cut. As global warming accelerates, we will be faced with countermeasures that will lead to other forms of environmental damage. We will have to choose between reducing our consumption and embracing technologies in various shades of dirty green.

The deep sea is so hard to reach that scientists and capitalists often end up collaborating to get there. For example, the findings in a recent Nature Geoscience paper were made possible in part by funding from The Metals Company.

The paper’s lead author, Andrew Sweetman of the Scottish Marine Science Association, noticed something odd during a 2013 expedition to study oxygen consumption in the deep sea.

Oxygen in our planet’s oceans and atmosphere typically comes from photosynthesis. It’s too dark for that to happen two miles below the surface. Dissolved oxygen can be carried downstream by currents, where it’s consumed by living organisms, Sweetman said. Yet his sensors showed that oxygen was also being produced far below. He had the sensors calibrated, but they still showed rising oxygen levels. He told his students to throw the sensors in the trash.

Then, in 2021, with funding from The Metals Company, he tried measuring oxygen using a different method involving chemical titration. The growth didn’t go away. Then he and his colleagues sampled deep-sea rocks for various experiments. They continued to produce oxygen, which he called “dark oxygen.” He considered the possibility that these metal-rich lumps acted like natural batteries. He worked with an electrochemist who helped him measure the voltage—enough to split water into hydrogen and oxygen.

The nodules grow at an astonishingly slow rate of a few millimeters per million years, so these undersea environments are tens or hundreds of millions of years old, Sweetman said. And some creatures live solely on the nodules.

The discovery could have major implications for understanding the evolution of life on this planet and other worlds with oceans — including moons of Jupiter and Saturn, which NASA plans to explore.

Not everyone is convinced. One researcher employed by The Metals Company told New Scientist he plans to write a rebuttal, arguing it is likely a contamination error.

Sweetman, for his part, doesn’t see his discovery, even if replicated, as a reason to abandon all mining plans — only to wait a little longer to understand the deep sea and how to limit extraction to preserve life down there. The extracted minerals could accelerate the race to wean ourselves off fossil fuels, he said, and climate change is affecting both the seas and the land. “Everybody wants their new cell phone, their new computer, their electric car,” he said. “We have to make tough decisions.”

The metals would be useful not only for EV batteries but also for systems that store and transport solar and wind energy, said Jennifer Dunn, a professor of biological and chemical engineering at Northwestern University. But AI is also creating an insatiable market for some of those same hard-to-find minerals — which can make it harder to avoid greed.

The trade-offs wouldn’t be so stark if people were willing to change their lifestyles. For example, Americans could invest in more public transportation—and actually use it. Dunn recalls the sneering response Americans received when former President Jimmy Carter suggested in 1977 that we turn down our thermostats in the winter and wear sweaters.

She said offshore mining shouldn’t be dismissed because the consequences of unabated global warming are so dangerous, but we need to know more about the risks. Could there be an unforeseen catastrophe, like the Deepwater Horizon oil spill? Scientists would need to assess not only the environmental consequences if everything went according to plan, but also the consequences if something went wrong.

Deep-sea habitats won’t recover once disturbed, at least not anytime soon—so over-exploitation could do irreversible damage, potentially driving species extinct before humanity even knows they exist. Climate change, of course, poses the same threat. There are no easy choices ahead.

FD Flam is a science columnist for Bloomberg Opinion and host of the podcast Follow the Science.