Today, Isometric issued the world’s first independently verified Ocean Alkalinity Enhancement (OAE) carbon dioxide removal (CDR) credits to Planetary. The 625 credits were generated from Planetary’s Tufts Cove project in Halifax, Nova Scotia and will be delivered to British Airways, Shopify, and Stripe. These credits are not only the first OAE credits, but also the first independently verified CDR credits from any marine carbon removal pathway.
These credits demonstrate that marine pathways like OAE can be accurately and robustly quantified, and highlight OAE’s potential to help scale carbon removal responsibly and fast. This marks a significant step forward for the CDR industry—setting the standard for all future OAE credits.
OAE is a promising pathway for carbon removal with the potential to remove billions of tonnes of carbon dioxide from the atmosphere. It can also be deployed using existing infrastructure and can help mitigate ocean acidification, benefiting marine life including coral reefs and shellfish.
The ocean is the world’s largest carbon sink, and OAE leverages this scale. Carbon dioxide naturally dissolves into the ocean from the atmosphere, primarily forming carbonic acid—which contributes to ocean acidification. OAE accelerates the Earth’s natural weathering process by adding powdered alkaline rocks or minerals to the ocean’s surface layer. These minerals react with carbonic acid to form stable bicarbonate ions—which safely store the carbon dioxide for tens of thousands of years.
As bicarbonate ions form, the concentration of carbon dioxide dissolved in the ocean decreases. This triggers a natural rebalancing process where the ocean absorbs more carbon dioxide from the atmosphere.
This milestone has been recognized by the wider carbon removal ecosystem.
Giana Amador, Executive Direct of the Carbon Removal Alliance, said:
“Isometric's issuance of the world’s first Ocean Alkalinity Enhancement credits to Planetary—a Carbon Removal Alliance member—marks an important milestone for marine carbon removal. The ocean is already the world's greatest carbon sink, and human innovation can help the ocean absorb even more carbon, and heal itself in the process. We look forward to working with Isometric and Planetary to ensure our industry continues to be categorically good for the planet, economy, and people as it grows to gigaton scale."
These credits were certified under Isometric’s industry-first Ocean Alkalinity Enhancement from Coastal Outfalls Protocol, which takes a scientifically rigorous approach to monitoring, reporting, and verification (MRV). The quantification methods in the Protocol were informed by Isometric’s research partnership with [C]Worthy, a leading marine research organization.
The protocol combines on-site measurements with peer-reviewed ocean models—such as the Regional Ocean Modeling System—to quantify the drawdown of atmospheric carbon dioxide. These models—extensively validated with real-world ocean data—make it possible to account for the full natural variability of the marine environment.
The data and calculations behind each OAE credit are fully transparent and publicly available on the Isometric Registry, providing a permanent audit trail for every credit issued and allowing all underlying information to be independently reviewed and scrutinized.
With scientific rigor, robust MRV, and full transparency underpinning the world’s first OAE credits, buyers can be confident that each Isometric credit represents one tonne of carbon dioxide durably removed from the atmosphere.
For more information on how Isometric quantified these credits, read the explainer here.
