Objective

DG MARE welcomed the participants, explaining that, by virtue of its potential to sequester carbon, there is huge interest in blue carbon, particularly among the scientific and conservation activist communities. Nevertheless, despite many research projects and scientific papers, there is still considerable uncertainty about its extent, its changes over time, its role in the carbon cycle and how human management can affect it. No EU country explicitly includes blue carbon in the inventories that it submits to UNFCCC. France aggregates mangroves with forests. Other EU countries group it with freshwater carbon where, at a national scale, it is a net emitter.

The objective of the meeting was to bring together ongoing EU projects on blue carbon in order to understand better what we know, what we don’t know and what we are doing to provide the means for reliable reporting and management of blue carbon ecosystems.

EU targets and accounting for the role of land use in climate are set in the Land Use, Land Use Change and Forestry (LULUCF) Regulation. DG CLIMA explained that currently land use represents a net sink. Removals are greater than emissions. The stocktake[1], published last May, indicates that the magnitude of this sink is reducing. An evaluation started in June 2024 to identify how the policy framework for the land sector is performing as an effective means of delivering on the key goals of an intermediate 2040 climate target and climate neutrality by 2050. This will include simplification, its coherence with other legislation such as the voluntary framework for carbon removals and the benefits of sustainable carbon products. A call for evidence has been published[2] .

Mangroves, saltmarsh and seagrass ecosystems can already be reported under the current regulation. The regulation also envisages an assessment of the feasibility of reporting greenhouse gas emissions and removals from additional sectors, such as the marine and freshwater environments subsequent to the adoption of an appropriate science-based reporting methodology and based on progress in reporting and the latest scientific information available.

The four projects considered here were:

• A study under Mission Ocean led by Trinomics which aims to identify what we know about how countries report blue carbon.
• C-Blues a research collaboration with China which aims to significantly advance knowledge and understanding of blue carbon ecosystems improve reporting of blue carbon, and promote the role of blue carbon in delivering climate policy commitments.
• MPA Europe which is mapping the optimal locations for marine protected areas in European seas using a holistic approach that considers both biodiversity and carbon sequestration, storage and deposition.
• OBAMA-Next which is producing a toolbox delivering information products for marine ecosystems.

There has already been informal contact between the project teams. Some organisations participate in more than one of them.

Ongoing projects and initiatives

Trinomics summarised their objectives. They are constructing a relational database of current reporting by EU Member States classified according to 2013 guidelines, maps of wetland distribution including changes and research on blue carbon measurement and enhancement. A first version of the database will be available in September this year. The project will end in April 2025.

The C-Blues collaborative project with Chinese universities started in April 2024 and will continue for four years. It is measuring and modelling, including using the Euro-Mediterranean Centre for Climate Changes Biogeochemical Flux Model, the carbon cycle in sites of all European sea basins and along the Chinese coast. It also has ambitions to extend the validity of its analysis on a global scale. The International Oceanographic Convention (IOC) is a partner.

They have identified 36 relevant databases. A manual for standard operation procedures is being prepared that will build on the 2013 IPCC guidelines, and potentially be adopted internationally. This could be ready by 2027. In addition to the accepted blue carbon ecosystems with rooted vegetation – saltmarsh, seagrass and mangroves – the project also covers cultivated and wild macroalgae. Work on a data management plan has begun.

The Obama-Next project is mapping seagrass distribution in Europe.

The MPA-Europe project is mostly focusing on biodiversity but are also constructing a database on organic carbon in sediments.

EMODnet (European Marine Observation and Data Network) is not a project but a network of over 120 organisations that can ensure permanent stewardship of data. European research projects that are collecting marine environmental and/or human activities data have a contractual obligation to make their data openly available. The EC aims to streamline this through EMODnet. Guidelines for projects to submit their data are available via the EMODnet Ingestion portal. In addition, EMODnet compiles and publishes several marine datasets/products that are relevant to blue carbon and are extremely keen to work with the projects to reduce duplication of effort. For example, Coastal Wetlands in European Waters, Seagrass Cover in European Waters and Macroalgal Canopy Cover in European Waters. As well as habitats, it includes several other marine datasets/products such as sedimentation rates since the beginning of the last century based on e.g., historical records of anthropogenic radionuclides. From September 2025 EMODnet-Geology will cover organic carbon in sediments.

Data Issues

The MPA Europe team were unable to attend the meeting but have informed DG MARE that the database on organic carbon will be published and could even be provided earlier than the end of the project. We need to check as early as possible that it can be merged with EMODnet data.

C-Blues will deposit data collected in the project with the detailed global database of the Smithsonian Institute as this is endorsed by IOC. DG MARE aims for interoperability of EMODnet with global standards. For instance, the bathymetry data collected by EMODnet contributors to the General Bathymetric Map of the Ocean (GEBCO).

Obama-Next has found some discrepancies between maps of seagrass available through EMODnet and the UNEP-WCMC global dataset. The EMODnet Seabed Habitats team replied that the European product aims to be a regional improvement to the global datasets, and aims to feed back into those global datasets.  It was noted that Obama-Next had identified additional local datasets from some countries such as Spain. The EMODnet Seabed Habitats team noted that there are some gaps, particularly in countries that are not represented in EMODnet Seabed Habitats, such as Spain. The Obama-Next project is ready to share the Spanish data.

RTD reminded the group that inclusion in UNFCCC reporting is dependent on data going back to 1990. Satellite images are available for those years although other data, such as salinity, is required. C-Blues will be assessing the sufficiency of these measurements.

Seagrass presents more of a challenge. The United States does not include it in its inventory. Japan has reported that it intends to include it in theirs although, presumably this is based on extensive monitoring. Neither is it clear how they can distinguish managed from unmanaged ecosystems.

Japan also claim to be able to include macroalgae although the method has not yet been published, at least in English. Some scientists feel this may be premature given the difficulties in validating carbon removal coefficients. C-blues are concerned that the low resolution of EMODnet bathymetry in some areas due to security concerns limits their ability to model its distribution and growth.

Next Steps

MARE suggested a second meeting, possibly in the beginning of 2025, when the study results are available. Other relevant projects could be invited. In the meantime, the EMODnet Geology team will examine the compatibility of MPA Europe’s database for organic carbon and the EMODnet Seabed Habitats team will examine the compatibility of habitat maps in the Smithsonian database and UNEP-WCMC global datasets with EMODnet.

[1]         Report on the operation of Regulation (EU) 2018/841 ("LULUCF Regulation") COM(2024) 195

[2]              https://ec.europa.eu/info/law/better-regulation/have-your-say/initiativ…