Year in Review: 2025 Marine Carbon Dioxide Removal Milestones

Sherry Lippiatt

2025 was a defining year for marine carbon dioxide removal (mCDR). Across abiotic pathways, like ocean alkalinity enhancement (OAE) and direct ocean capture and storage (DOCS), the mCDR field began to shift from promise to proof. Pilots were advanced, the first verified credits were delivered, and companies demonstrated that they are building the foundation to get to commercial scale. These are some of the major industry highlights that we are celebrating as 2025 comes to a close:

• Planetary delivered the first-ever verified OAE credits through Isometric from their Halifax Harbor, Canada site. The company subsequently announced a landmark $31M offtake deal with Frontier for 115,000 tons of future removal.

• Ebb Carbon secured a first-of-a-kind National Pollution Discharge Elimination System permit and began operating their OAE system at Project Macoma in Washington State. Ebb also announced a strategic partnership with the Saudi Water Authority to integrate their technology into desalination plants in Saudi Arabia.

• Captura began operating its third and largest pilot system in Hawai‘i (1,000 tons), signed a 30,000 ton offtake with Mitsui, and, together with Equinor, completed a major technology qualification program validating its DOCS system for commercial deployment.

• Equatic closed an $11.6M Series A to accelerate engineering scale-up and plans to launch their first demonstration-scale plant in Singapore, slated to begin operation in early 2026.

• Capture6 announced $27.5 million in Series A investment to scale their combined direct air capture / OAE technology at existing industrial facilities. 

• SeaO2 raised over €2M to transition their DOCS system from prototype to pilot plant in the Netherlands.

• CarbonBlue and PRONOE announced integrations with desalination facilities in Israel and the Canary Islands, respectively.

Beyond project development, the mCDR ecosystem also matured at an institutional level:

• Woods Hole Oceanographic Institute advanced field trials and secured the first Marine Protection, Research, and Sanctuaries Act permit from the Environmental Protection Agency, setting an important regulatory precedent for scientific research in U.S. waters.

• Carbon to Sea and partners released an OAE data management protocol, strengthening consistency and interpretability.

• Isometric published the first registry protocol for direct ocean capture and storage (DOCS) deployments, creating a crediting pathway for DOCS suppliers.

• The Carbon Business Council launched the mCDR Coalition, bringing together suppliers, researchers, and enabling organizations.

• The research community continued to advance our understanding of the potential ecosystem risks from mCDR activities and new initiatives signaled the maturation of the field: Carbon to Sea published a draft Environmental Impact Monitoring Framework that details specific monitoring needs and considerations for OAE, while Ocean Visions announced a partnership with Fugro to develop an Environmental Impact Assessment Framework to identify and minimize potential negative impacts of mCDR projects.

• On the policy front, the EU’s Carbon Removal and Carbon Farming program took the first steps towards establishing an OAE methodology, which would create new incentives for mCDR projects in the region.  

The year saw suppliers move from planning and permitting to full end-to-end execution. mCDR is now producing measurable, verifiable carbon credits. 2025 also brought major progress on the scientific validation, regulatory foundation, and shared infrastructure needed for mCDR at scale. With multiple new deployments on the horizon, the coming years will continue to prove out the promise of ocean pathways to deliver credible, safe, and effective carbon removal.

Importantly, alongside growing policy momentum and technological advancements, we’re hopeful that updates included in the forthcoming Science Based Targets Initiative Corporate Net‑Zero Standard V2.0 (expected in 2026) will increase demand for durable carbon removal credits like OAE and DOCS. The new standards are expected to explicitly allow companies to use CDR to neutralize a company’s residual emissions, which would bring more buyers into the market. In addition, Article 6 of the Paris Agreement is inching towards development of requirements and methodologies that would establish a credible, transparent framework for purchasing and trading of carbon removal credits across borders and unlock global finance for carbon removal projects.

As the field continues to develop, in the year ahead [C]Worthy will remain focused on strengthening the scientific and digital infrastructure that underpins mCDR quantification. In 2026, we will continue developing and launching open-source ocean modeling tools to advance transparent and trustworthy measurement, reporting, and verification of mCDR deployments. These advances will help anchor the field in transparency, integrity, and shared scientific confidence.