Senara Wilson Hodges was nervous. It was April 2023 and she had shown up early to a meeting of the local council in St. Ives, a bucolic seaside community of some 10,000 souls in southwest England. Wilson Hodges, a keen surfer and lifelong environmental campaigner, had joined the council several months earlier to influence some of the issues facing her home: the old town center, once home to fishermen, was being hollowed out by tourism, and development was running rampant. But that night, she had something else on her mind.
Wilson Hodges had been researching a Canadian start-up called Planetary Technologies and was concerned about their activities in St. Ives Bay. Like many of her neighbors, she had only learned about the company a few weeks earlier, when an article in The Times detailed how, over several days during the previous fall, Planetary had added a slurry of magnesium hydroxide to the local water company’s sewage pipe and pumped it into the sea off St. Ives Bay.
Wilson Hodges had been researching a Canadian start-up called Planetary Technologies and was concerned about their activities in St. Ives Bay. Like many of her neighbors, she had only learned about the company a few weeks earlier, when an article in The Times detailed how, over several days during the previous fall, Planetary had added a slurry of magnesium hydroxide to the local water company’s sewage pipe and pumped it into the sea off St. Ives Bay.
For Wilson Hodges, the secretive test rang alarm bells. She quickly found that others in town were equally concerned. How could they sleep soundly while an unknown company was pouring chemicals into the sea, potentially harming the local marine life? Was Planetary’s science even sound? And why were they only finding out now? Most alarmingly to locals, the company planned to press ahead with a much larger trial in the summer. (...)
The heated debate that ensued has pitted old-school environmentalists against climate-tech evangelists, caused a rift with the council in the neighboring town of Hayle, and led the Environment Agency to commission an audit of the project. The regulator will soon deliberate on whether a larger trial can proceed. If it does, it could take place almost two years after Planetary had initially planned.
The controversy in St. Ives has played out as a growing number of start-ups and researchers around the world prepare to conduct their own ocean alkalinity enhancement trials. For all of them, St. Ives could provide a useful case study in how to convince local communities of their good intentions and scientific rigor. Whether Planetary is successful could help determine which, if any, of these technologies are adopted more widely, and how quickly they grow. For locals opposed to the trial, Planetary’s work also raises fundamental questions: After messing with natural ecosystems for so long, how do we repair the damage without causing more? And who gets to decide where that takes place?
The St. Ives council vote marked the culmination of a turbulent few weeks for Mike Kelland, Planetary’s 44-year-old CEO. Kelland, a former software entrepreneur, had cofounded Planetary in 2019 because he believed ocean alkalinity enhancement to be the most promising solution to a problem increasingly dogging global action on climate change: how to not only cut carbon emissions dramatically but also remove those already accumulated in the atmosphere.
Interest in ocean alkalinity enhancement, as well as other solutions that fall under the broad umbrella of geoengineering, has risen alongside a growing consensus that engineered carbon removal is unavoidable. The Intergovernmental Panel on Climate Change (IPCC) now says removing carbon from the atmosphere will be necessary to limit warming to below 2 °C by the end of the century. Even if we blow past that point, carbon removal could help achieve net-negative emissions and reduce global warming in the long run.
Companies are already removing carbon by planting trees and seagrass, and even by directly filtering it out of the air. But in terms of sheer scale, ocean alkalinity enhancement is one of the most potent options. The IPCC estimates that it has the potential to remove up to 100 gigatonnes of carbon dioxide per year, more than twice our annual greenhouse gas emissions and likely far more than any alternative.
What’s more, the ocean is already the world’s largest store of carbon and has absorbed roughly 30 percent of anthropogenic carbon dioxide emissions since the Industrial Revolution. Some of that carbon dioxide is neutralized over time as rain weathers rock and washes minerals into the sea, causing a chain of reactions that alkalinity enhancement essentially simulates at hyper speed.
Planetary, which eventually plans to sell carbon credits that other companies could use to offset their own emissions, developed its approach with a small team of marine scientists. It involves releasing magnesium hydroxide, an alkaline substance that occurs in nature as the mineral brucite but can also be manufactured synthetically. In the ocean, the chemical binds carbon from carbon dioxide already dissolved in the water into bicarbonates, which stay stable for thousands of years. The resulting carbon dioxide deficit allows the sea to draw more from the air, thereby lowering its concentration in the atmosphere. (...)
Planetary has emphasized that magnesium hydroxide is far from an unknown quantity. It is widely used in wastewater treatment—for example, to help filter out heavy metals—and it’s the main ingredient in drugstore laxatives and antacids like Milk of Magnesia. Still, adding anything to natural environments can be contentious. “People hear chemistry and they don’t like that,” says David Ho, a geochemist and professor of oceanography at the University of Hawaiʻi at Mānoa.
Ho himself is involved in several ocean alkalinity enhancement projects as a researcher, including in the United States and Iceland, and is cofounder and chief science officer of nonprofit research organization [C]Worthy, which makes open-source software to quantify the efficacy and side effects of marine carbon removal. Like others in the space, he says the threat to local ecosystems posed by ocean alkalinity enhancement should be fairly low. But there are still potential risks. Adding large amounts of ground-up minerals to the sea could raise the water pH too quickly or add toxic trace metals, which could harm marine organisms.
Other researchers have also flagged that changing the carbon chemistry of the ocean could have unintended side effects, such as slowing the growth of microalgae that provide food for a vast range of sea creatures. On the other hand, lowering the ocean’s acidity could benefit shell-forming organisms and corals.
The point is, we don’t really know what exactly will happen: so far, scientists have mainly studied ocean alkalinity enhancement in labs or have only modeled its effects. While a handful of other companies have conducted small field studies, Planetary is one of the first to undertake trials at a larger scale. “It’s the unknown unknowns that get you sometimes in nature,” Ho says. “Things we didn’t think of.”
Nevertheless, like Ho and many other scientists in the field, Kelland is convinced that any remaining questions about the technology’s efficacy and impacts can only be answered in the open ocean. “There really is no substitute for real-world work in this space,” he says.
That message did not land as intended in St. Ives. When Planetary went public with its plans for the bay in the spring of 2023—and, in the process, first widely disclosed the details of its experiment from the previous fall—local news led with screaming headlines about dumping laxatives in the ocean.
A series of community meetings organized by the company did little to placate outraged residents. A few days after the St. Ives council vote, Wilson Hodges’s protest drew hundreds of people to a beach near the wastewater pipe. Forced into damage control, Kelland later hosted a three-hour Zoom meeting for the community, fielding pointed questions about ecocide and whether he would put profit over nature.
Planetary and South West Water, a private utility, were not required to notify the public of their initial experiment and, given the small dosage, decided it did not merit an official announcement. The uproar months later caught Kelland off guard, and he has since said that it was a mistake not to publicize the test. “We were surprised, and we shouldn’t have been,” he says. “That really put us on the back foot.” (...)
Like Rance, Wilson Hodges is keenly aware of the bay’s role as a test bed that could influence how geoengineering proceeds around the world. But rather than lending the project urgency, she feels this makes a strong case for holding companies like Planetary to account. After all, the industry is in its early stages, and there are few established rules and procedures around ocean alkalinity enhancement. “We’re a little guinea pig case study,” she says.
Image: Mike Newman
[ed. Smart people doing dumb things. Failure to inform communities that you're dumping chemicals into their water, whatever they might be, and not having the foresight or good common sense to even imagine local concern and opposition is just dumb tech hubris. And this applies to any experiments using a public resource. We'll probably see a lot more of this as increasing levels of climate desperation set in.]
