Marine carbon removal credits sold, 2020-2025
| Producer | Method | Tons | Year of Sale |
|---|---|---|---|
| Vesta | Marine rock weathering | 3,333.3 | 2000 |
| Ebb Carbon** | Alkalinity enhancement | 256 | 2021 |
| Running Tide | Biomass sinking (wood waste, seaweed) + alkalinity enhancement | 25,000 | 2023 |
| Equatic | Seawater electrolysis + alkalinity enhancement | 62,000 | 2023 |
| CREW Carbon | Alkalinity enhancement | 71,878 | 2024 |
| Ebb Carbon* | Alkalinity enhancement | 350,000 | 2024 |
| Captura | Direct ocean capture | 30,000 | 2025 |
| Planetary Technologies | Alkalinity enhancement | 115,000 | 2025 |
| Gigablue | Biomass sinking (phytoplankton) | 200,000 | 2025 |
| Total: | Up to* | 857,467.3 |
Data compiled by Brad Warren, GOH - brad@globaloceanhealth.org
Data sources, by firm
All transactions reported are from publicly disclosed data on “durable” removals, believed to sequester carbon for centuries or, in some cases, 1,000+ years. Most transactions represent advance market commitments, in which purchasers buy (or commit to buy) marine carbon removals to be delivered in the future (often a strategic investment in building the field).
Captura:
Captura announces sale of carbon removal credits and strategic partnership with Mitsui O.S.K. Lines - Captura, Mar 2025
CREW Carbon:
CREW Carbon Signs $32M Offtake Agreement with Frontier - Yale Ventures, Dec 2024
Ebb Carbon*: Up to 350,000 tons sold in advance market commitment.
Ebb Carbon and Microsoft: A Landmark Carbon Dioxide Removal Agreement - April 2025
Ebb’s 2021 credit sale**: Amount purchased was not initially disclosed, but a 2022 report in Trellis (formerly GreenBiz) described the agreement as an advance purchase of 256 tons:
Stripe Climate increases carbon removal commitments to $15 million, adding four new companies - Stripe, Dec 2021
A dream team for ocean carbon capture? - Trellis, May 2023
Equatic:
Equatic Launches Low-Cost, Gigaton-Scale Technology to Decarbonize at Unprecedented Speed - Equatic, May 2023
Gigablue:
Gigablue Announces Largest Ocean Carbon Removal Agreement with SkiesFifty, Capturing 200,000 Tons Over Four Years - Gigablue, Jan 2025
Planetary:
Frontier Commits $31M to Planetary to Scale Ocean Carbon Removal - Planetary Tech, Aug 2025
Planetary Signs $31 Million Ocean Carbon Removal Deal with Buyers Including Google, Stripe, H&M - ESG Today, Aug 2025
The World’s First Verified OAE Credits - Planetary Tech, June 2025
Running Tide:
Running Tide becomes Microsoft’s first open ocean-based carbon removal supplier - PR Newswire, Mar 2023
Running Tide, which sold carbon credits for sinking seaweed, shuttering operations - Seafood Source, June 2025
Vesta: Can this mineral help boost the carbon stored in oceans? - Trellis, Aug 2021