Stop Marine Geoengineering Experiments in Cornwall

Planetary Technology, a Canadian company, plans to dump 450 tonnes magnesium hydroxide into the sea in St. Ives Bay, Cornwall UK as part of an ocean alkalinity enhancement scheme, which raises concerns for the ‘Hands Off Mother Earth! Alliance. The experiment poses a potential serious risk to marine ecosystems and the Celtic Sea grey seal population.

Planetary Technology claims that the Ocean Alkalinity Enhancement (OAE) experiment will decrease the acidity of seawater and remove carbon. In theory, this would happen by adding magnesium hydroxide to the water in the bay, however this approach has not been proven.

Other concerns about the experiments by Planetary Technology raised by civil society include:

• The company has commercial interests, for example Planetary has sold CO2 credits to Shopify and Stripe without yet removing any CO2.
• Magnesium hydroxide occurs naturally as brucite, but the deposits are small. For industrial use, therefore, it is usually precipitated from sea water and then dried at high temperatures. > - This process requires so much energy that producing magnesium hydroxide may use more carbon dioxide than is captured through the enhanced weathering process.
• There are a number of concerns about the technical approach and safety of OAE. A recent article in Nature highlights the technical challenges around the technology.