I n early 2023, members of the Cornwall Marine Liaison Group gathered for a meeting about marine biodiversity featuring a presentation with the Canadian company Planetary Technologies. Over a video call, staff presented their plan to add magnesium hydroxide to the waters of St. Ives Bay, a picturesque crescent on England’s southwest peninsula, via a wastewater pipe. The company pitched the three-month trial as a safe form of carbon dioxide removal—an “antacid for the sea,” says Sue Sayer, founder and director of the Seal Research Trust, who was at the meeting. For the audience, most of whom were highly attuned to the risks of climate change, the idea seemed like something simple and safe.
Months later, though, concerns had surfaced. At a second meeting, this time with townspeople in nearby Hayle, audience members assailed the company with questions: Why St. Ives Bay? What about wildlife? Shortly after that, protesters gathered on a sloping hillside overlooking the bay, holding signs reading “Planetary can stick it up their waste pipe” and demanding more scientific oversight.
