What is carbon dioxide removal?
Limiting global warming to 1.5°C above pre-industrial levels requires urgent and rapid reductions in greenhouse gas emissions However, such efforts will not be enough on their own. Actively removing carbon dioxide (CO₂) from the atmosphere is now also recognised as an essential requirement for meeting the Paris Agreement goals.
Marine carbon dioxide removal (mCDR) takes advantage of the fact the ocean is the largest exchangeable surface reservoir of carbon and uses that capacity for long-term storage. mCDR techniques aim to replicate or speed up the biological, chemical and physical processes that enable seawater to absorb CO₂ from the atmosphere.
However, our understanding of mCDR is still developing. Major knowledge gaps and challenges must be addressed before these techniques can safely be deployed at the scale needed to tackle climate change.
Why is mCDR research important?
The ocean plays a vital role in regulating Earth’s climate. By improving our understanding of proposed mCDR techniques, we can explore if, and how, the ocean could be responsibly used to store more carbon and help mitigate climate change.
Without researching mCDR, decision-makers would lack the critical information needed to judge whether to use these approaches alongside emissions cuts. This could slow progress on climate targets and increase risks to people, ecosystems and economies worldwide.
Key questions remain about how effective mCDR methods are, their costs, environmental and social impacts, and whether their effects can be measured and verified over time. Independent research is essential to answer these questions and ensure any future use of mCDR is safe, fair and effective.
How does NOC study mCDR?
The National Oceanography Centre leads UK research to fill critical knowledge gaps about mCDR. Our work combines advanced technology, field observations, modelling and collaboration with partners worldwide.
Key projects include:
NOC is the scientific and technical lead of this Horizon Europe-funded project, through which common assessment frameworks, governance structures and tools are being developed to enhance our ability to evaluate different mCDR techniques. This helps determine how mCDR can support climate mitigation and adaptation strategies.
Find out more about the SEAO2-CDR projectPart of the NERC National Capability Programme, this project is improving our understanding of ocean-based climate solutions by:
- Analysing long-term ocean datasets to provide reliable, relevant baselines for future mCDR comparisons.
- Combining advanced ocean models with societal metrics to assess mCDR impacts locally and globally.
- Advancing methods for monitoring, reporting and verification (MRV) using autonomous sensors and platforms.
- Engaging with policymakers, regulators, businesses and the public to share insights and support informed decisions.
In partnership with Fugro and Integral Consulting, and supported by Ocean Visions, we are helping develop a standardised framework to assess environmental risks and interactions linked to mCDR research. This framework will guide project developers, regulators and communities in evaluating mCDR options.
TerraFIRMA supports the development of the UK Earth System Model which produces climate projections that feed into Intergovernmental Panel on Climate Change (IPCC) reports. Simulations of global-scale applications of different mCDR approaches have been undertaken to allow for the potential effectiveness and environmental impacts, risks and co-benefits of these climate mitigations approaches to be evaluated.
Project websiteWhat research is NOC doing on mCDR?
Our research is helping shape responsible and effective guidelines for mCDR. These studies provide evidence to help decision-makers weigh up the benefits, costs and practicalities of different approaches, supporting more informed climate policy and action.
Notable recent publications include:
Benefit-cost ratios of carbon dioxide removal strategies
Cael, B B 
ORCID: https://orcid.org/0000-0003-1317-5718; Goodwin, P; Pearce, C R ORCID: https://orcid.org/0000-0002-4382-2341; Stainforth, D.
2023
Benefit-cost ratios of carbon dioxide removal strategies.
Environmental Research Letters, 18 (11), 114003.
10.1088/1748-9326/acffdc
2023
Article
Global‐scale evaluation of coastal ocean alkalinity enhancement in a fully coupled Earth system model
Palmieri, Julien ORCID: https://orcid.org/0000-0002-0226-5243; Yool, Andrew ORCID: https://orcid.org/0000-0002-9879-2776.
2024
Global‐scale evaluation of coastal ocean alkalinity enhancement in a fully coupled Earth system model.
Earth's Future, 12 (3).
10.1029/2023EF004018
2024
Article
Biological carbon pump sequestration efficiency in the North Atlantic: A leaky or a long‐term sink?
Baker, Chelsey A. ORCID: https://orcid.org/0000-0002-0840-2333; Martin, Adrian P. ORCID: https://orcid.org/0000-0002-1202-8612; Yool, Andrew ORCID: https://orcid.org/0000-0002-9879-2776; Popova, Ekaterina ORCID: https://orcid.org/0000-0002-2012-708X.
2022
Biological carbon pump sequestration efficiency in the North Atlantic: A leaky or a long‐term sink?
Global Biogeochemical Cycles, 36 (6).
10.1029/2021GB007286
2022
Article
Sharing our knowledge
We actively share our findings through podcasts, videos, talks and events to make our science accessible and encourage public dialogue about ocean-based climate solutions. We also regularly contribute to conferences and discussions worldwide, bringing together experts, stakeholders and the public to advance understanding and guide responsible mCDR development.
Find out more
To find out more about our work on marine carbon dioxide removal and other climate-related research, visit NOC’s research pages.