Scientists highlight research priorities for robust monitoring of marine carbon dioxide removal

A new report suggests improved monitoring systems are essential before marine Carbon Dioxide Removal (mCDR) could help meet global climate targets. 

Carbon Dioxide Removal (CDR) methods are being developed and piloted, including marine approaches that harness the power of our ocean, to help tackle removing legacy carbon from the atmosphere. 

These solutions could be vital for addressing residual emissions and achieving the Paris Agreement’s climate goals once greenhouse gas emissions have been cut. 

To ensure these methods are both effective and safe, a rigorous process known as monitoring, reporting and verification (MRV) is essential. MRV involves collecting and independently verifying data on marine CDR activities - measuring how much carbon dioxide is removed, assessing durability, identifying uncertainties, and evaluating environmental impacts. This structured approach provides transparency and safeguards ocean health as the world explores new ways to tackle climate change. 

The importance of MRV is addressed in a European Marine Board Future Science Brief on ‘Monitoring, Reporting and Verification for marine Carbon Dioxide Removal’, published today (17 November 2025) by an international working group of thirteen researchers, including the National Oceanography Centre’s (NOC) Dr Chelsey Baker. 

The report clarifies the current scientific, technical and regulatory challenges that must be addressed to develop appropriate and reliable monitoring, reporting and verification (MRV) for any future mCDR activities, which will safeguard ocean health and those who depend on it. 

According to the ‘State of Carbon Dioxide Removal’ report, mCDR methods contribute less than 0.1% to current removal efforts, but this field is growing rapidly. The potential impacts on the marine environment are not yet clear but could be significant. 

The document emphasises, among other points, research knowledge gaps that present major challenges for the practical implementation and efficiency of mCDR methods in the ocean. Among them are uncertainties about the processes and impacts, and the duration for which the carbon could be stored in the ocean. 

Dr Helene Muri, Senior Researcher at NILU and Norwegian University of Science and Technology (NTNU), Norway, and Dr Olivier Sulpis at CEREGE - Aix-Marseille University, CNRS, IRD, France, lead the project team. 

Dr Muri commented: “No mCDR method currently has a sufficiently robust, comprehensive MRV in place. This means that efficient and safe deployment of mCDR methods cannot be ensured at the moment. 

“If we would like to consider the use of mCDR, we have to invest in knowledge generation for MRV now. That will enable the development of fit-for-purpose MRV frameworks if or when we reach large-scale mCDR implementation.” 

Dr Baker added: “It has been a privilege to be involved in this report synthesising the current state of knowledge and capability for MRV of mCDR activities. 

“MRV requirements are pushing the limits of our ocean observing and prediction capabilities. Advancements in these capabilities will support rigorous assessments of mCDR activities, and along the way we will uncover much more about how the interplay of biology, chemistry, and physics in the ocean supports carbon storage and sustains ecosystems, which is an exciting prospect.” 

Read the report in full: https://www.marineboard.eu/publications/MRV_for_mCDR