To meet climate goals, experts agree that the world will need to curb CO2 emissions, and apply carbon removal solutions with large scaling potential, such as marine carbon dioxide removal (mCDR), to tackle the existing atmospheric carbon dioxide build-up and the CO2 footprint of hard-to-abate sectors.
Known as Earth’s largest CO2 cleansers, oceans are removing ~30% of anthropogenic carbon emissions annually and storing approximately 6x more than the other storage systems, including land and the atmosphere.
These natural carbon “sponges” have inspired a growing field of mCDR innovations.
As interest in these technologies accelerates, the key question is no longer whether mCDR holds promise, but whether the progress underway is being matched by the science, policy support, and safeguards needed for responsible scale.
To gain a better perspective on the current state of mCDR, we talked to seasoned representatives from Canada, the U.S., and Europe, who shared views on what currently moves this sector and what can support its responsible advancement.
A global mCDR momentum on the rise
Canada is aligning actions with assets, seemingly working on becoming a leading global mCDR hub, while the UK, Australia, Singapore, Japan, and New Zealand are busy exploring mCDR possibilities.
In the U.S., 2025 showed a political divide on climate issues, while 2026 has brought the introduction of the first bipartisan and bicameral mCDR bill in Congress, and a recent Rainey Center study identified strong mCDR support from both Republican and Democrat voters.
At the same time, EU scientists and field specialists are calling for deeper research into mCDR technologies to better determine their exact carbon removal power and impact on ecosystems.
Canada shines bright on the global mCDR map
Carbon Console tracks the rapidly expanding carbon removal sector in Canada, showing data on companies, projects, capacity, and technologies in real time.
From the 85 companies displayed on this platform, 30% are focused on mCDR activities, spanning across technologies such as OAE, DOC, river alkalinity enhancement, macroalgae cultivation, and marine biomass sinking.
One of the companies currently active in Canada is CarbonRun, which is working on the West River Pictou river alkalinity enhancement project in Nova Scotia.
Talking to our team, CarbonRun co-founders Edmund Halfyard, PhD, and Luke Connell share their work on river alkalinity in Nova Scotia initially emerged as a necessary tool to address the declining water quality in this Canadian province, caused by acid rain triggered through fossil fuel burning.
Inspired by river liming done in Sweden and Norway, Nova Scotia also introduced this technology in the early 2000s, which also happens to be the field of specialty of Edmund Halfyard.
Upon coming to a realization that river liming can actually help capture CO2, Edmund Halfyard joined forces with Luke Connell and the company’s other co-founder, Shannon Sterling, shaping out CarbonRun and developing projects from an idea level to actual deployments.
Commenting on the mCDR ecosystem in Nova Scotia, Connell and Halfyard say that the province is attractive for carbon removal companies, and Canada as a whole seems to be on track to seize the huge economic opportunity presented by the growing CDR market.
What makes Canada an appealing carbon removal location, Halfyard says, is the abundance of natural resources, a strong scientific and academic fleet, a well-informed and engaging community, and a supportive government, especially in Nova Scotia, which he also hopes to see reflected on a federal level.
While for an approach like river alkalinity enhancement, Halfyard notes that there’s a long history of freshwater research and more mature science, for pathways like OAE, he observes, there currently is a science base to allow for some more advanced projects to proceed with some guardrails.
Halfyard believes that the present science on approaches such as OAE can support a limited-scale deployment, which, in turn, can attract other funding to support that science.
Relevant: Carbon180, The Carbon Business Council & Ocean Conservancy Launch New mCDR Forum
The U.S. is trailblazing in mCDR policy
In February 2026, the United States had a major positive mCDR development when a bipartisan and bicameral bill was introduced to Congress, potentially opening doors for publicly funded mCDR research.
The ReSCUE Oceans Act, introduced by Senators Murkowski (R-AK) and Schatz (D-HI) and Representatives Bonamici (D-OR-01) and Carter (R-GA-01), could create a foundation for a much-needed federal support framework for the responsible growth of mCDR technologies.
U.S. NGO Carbon180, whose work advocates for carbon removal policy support and CDR development aligned with community well-being, and whose team has made edits to draft versions of the bill in coalition with other organizations, welcomed this landmark motion, seeing it as progress in the right direction.
Commenting on what the bill means for the mCDR field,Amanda Vieillard, Carbon180’s Director of Ocean Policy, shares:
“It’s the first of its kind mCDR-specific bill that we’ve seen, and what’s most important is that it focuses on mCDR research and development (R&D) supported through public funds.
The scale at which mCDR needs to ramp up and the amount of research that we need is really only possible with federal public dollars. The fact that this bill would create a dedicated mCDR NOAA program as a kind of foundation within the federal ecosystem to support the necessary R&D is exactly what we need to see for this field to really develop and move forward in any kind of sustainable way.”
To Vieillard, the responsible future scaling of mCDR needs to be based in robust research, rigorous MRV, and strong safeguards that would back work rooted in scientific evidence.
Moving forward, she points out that enhancing the monitoring, reporting, and verification (MRV) and studying in-depth the overall ecosystem impact should be the primary goals when thinking about mCDR development.
Read more: U.S. Congress Now Considering First mCDR Research Bill
EU scientists officially call for further mCDR research
Towards the end of 2025, a report commissioned by the European Marine Board and put together by an expert group under the leadership of senior researcher Helene Muri reviewed all existing data on mCDR to date, concluding that the field is not yet prepared for large-scale deployment.
The expert team stressed that deploying mCDR technologies at scale despite the lack of evidence and thorough evaluation could actually cause more harm than bring climate benefits, pointing to the lack of reliable carbon removal measurement as one of the main challenges faced by the mCDR sector.
Muri says that since the report was published, there have been several encouraging developments on some of the key points raised in the publication, and some policy processes were already underway at the time it came out.
“In the EU, CRCF implementation has moved forward as the Commission adopted rules on certification schemes, certification bodies, and audits, and then adopted a Delegated Act in February setting methodologies for permanent carbon removals. Internationally, the BBNJ entered into force, calling for conservation and sustainable use of marine biodiversity.
And any mCDR projects in areas beyond national jurisdiction, or within national jurisdictions but with possible risks to biodiversity beyond, will have to comply with this, meaning robust environmental impact assessments (EIAs), ongoing monitoring, and disclosure through the emerging BBNJ process, strengthening the governance frameworks around mCDR,” she says.
Muri also notes clear research funding signals prioritizing environmental safeguards, such as calls looking to study how OAE could affect marine species, and, in her opinion, the strong mCDR presence at the Ocean Sciences Meeting in Glasgow is an indicator of how quickly the scientific evidence base and MRV-relevant research are growing.
When asked about what a responsible mCDR development should look like going forward, she says that over the coming 2-3 years, this could be prioritizing disciplined, MRV-led research and piloting, rather than rapid scaling of credited tonnes.
Are mCDR technologies safe and ready for widespread deployment?
While packed with CO2-curbing potential and already triggering a wave of pilots and policy signals, mCDR technologies need further science-backed proof of environmental safety and CO2 removal performance to scale safely.
Relevant entities such as the U.S. National Oceanic and Atmospheric Administration and the European Marine Board have published work that calls for more substantial evidence on mCDR to ensure its responsible development.
In an effort to narrow this knowledge gap, Carbon Direct and Microsoft have been releasing high-quality mCDR criteria since 2021, and guided by science-backed roadmaps like these, companies including CarbonRun, Limenet, Ebb Carbon, Captura, Equatic, Phantom Technologies, and many others are currently advancing mCDR and locking in contracts with corporate buyers.
Scientists are rightfully calling for more mCDR research, yet mCDR stakeholders also highlight that the climate is at a tipping point where waiting and inaction could cause more harm than cautiously deploying small-scale mCDR that would serve for both knowledge building and securing funding for science.
Besides companies investing in more mCDR research, governments also need to back mCDR studies, and the work currently being done in this regard in the U.S. could set up a blueprint for other regions to follow.
The oceans can once again help us tackle CO2 pollution as long as effective mCDR is deployed safely and in alignment with environmental and social well-being, ensured through scientific data and evidence.
FAQs
What is Marine Carbon Dioxide Removal (mCDR)?
mCDR technologies aim to enhance the absorption and storage of additional CO2 in ocean and/or seawater on top of the naturally absorbed amounts.
What kind of mCDR categories are there?
In a general sense, mCDR technologies can be categorized into biological and non-biological methods. These two categories branch out into a number of different approaches.
Which technologies and pathways fall under mCDR?
In the biological mCDR category, there are approaches such as marine bioenergy with carbon capture and storage (BECCS), blue carbon enhancement, and ocean fertilization, to name a few, while on the non-biological, engineered side there is direct ocean capture (DOC), ocean alkalinity enhancement (OAE), and market players are also exploring hybrid pathways.
