Current Landscape

Marine carbon dioxide removal (mCDR) encompasses a suite of emerging strategies that harness the ocean’s capacity to capture and store atmospheric CO₂. A diverse range of methodologies are under exploration—ranging from nature-based approaches like seaweed cultivation and ocean afforestation to technological interventions such as ocean alkalinity enhancement (OAE), electrochemical processes, and artificial upwelling. The developer ecosystem is still at an early stage, with most activity focused on laboratory studies, small pilot projects, and a handful of field trials concentrated in national coastal waters. The sector has seen the filing of 40 patents of which 13 have been granted, underscoring the growing role of technology and innovation in advancing the space.

Investments

Cumulative investments have now surpassed $ 250 million showing a steady rise since 2022 with an uptick in both public and private R&D investment: governments in the US, EU, and Asia-Pacific have collectively committed over $100 million to field trials, MRV standards, and cross-disciplinary research. The U.S. Department of Energy has committed over $36 million through programs like SEA-CO2, while NOAA and NOPP have announced another $24 million toward advancing marine CDR science and monitoring frameworks. In Europe, Horizon and Germany’s CDRmare are supporting feasibility and impact assessments.

Private investment is increasing, with a mix of equity funding, venture capital, philanthropic support. Investment inflows since 2020 show a growing share of equity-based financing (69%), complemented by public grants and early-stage philanthropic support.

Offtake activity is gaining momentum, now exceeding 450,000 tonnes, with key suppliers such as Gigablue, CREW Carbon, Aquatic, and Carbon Run, and buyers including SkiesFifty, Frontier, and Boeing leading demand. While June 2025 has recorded only three deals compared to 14 in 2024, the total contracted volume has already surpassed last year — reaching 230,000 tons versus 140,000 tons in 2024 — signaling larger deal sizes and growing market confidence.

Registry issuance has just started with Isometric issuing the first few credits for Planetary’s OAE project in Nova Scotia, Canada.

cCarbon Viewpoint

Over the next few years, marine CDR is likely to remain an R&D-intensive sector where public funding and advance market commitments are crucial to progress. If key challenges around robust monitoring, reporting, and verification (MRV) as well as environmental safety are resolved, marine methods could become a major pillar for large-scale carbon removal.