Polar oceans could help mitigate climate change — but science and policy are not yet ready to recognise them
: A new review by researchers of the Horizon Europe project POMP maps what is known — and what remains uncertain — about “polar blue carbon”, and sets out what is needed before carbon-rich Arctic and Antarctic habitats can be better recognised and integrated into climate and conservation policy.A new review by an international team of polar scientists, published within the Horizon Europe project POMP (Polar Ocean Mitigation Potential), assesses whether the Arctic and Antarctic oceans could be better incorporated into the frameworks used to address climate change and protect biodiversity. The review examines which polar habitats could be managed for their carbon-storage benefits, what currently limits their inclusion in policy frameworks, and what is needed to close the most important scientific and governance gaps.The Arctic and Antarctic represent around 20% of the global ocean and are experiencing rapid environmental change, with parts of the Arctic warming at up to four times the global average rate. As sea ice retreats and habitats shift, the processes through which polar ecosystems capture, transport and store carbon are also changing — yet polar systems remain largely unrecognised within blue-carbon approaches that have traditionally focused on tropical and temperate coastal ecosystems such as mangroves, salt marshes and seagrass meadows.The review groups polar blue-carbon habitats and pathways into three categories. Arctic salt marshes and seagrass meadows already have relatively strong evidence for their carbon-storage potential. Kelp and other macroalgal habitats are expanding in some polar regions, but are harder to assess because much of the carbon they capture may be transported away from the habitat. Less understood pathways include phytoplankton, microphytobenthos and ice-associated algae, and carbon stored in fjord, shelf and deep-sea sediments. For most of these systems, robust estimates of extent, carbon stocks and long-term sequestration remain limited, and the direction of future change is often unclear: some processes could increase carbon uptake, while others — such as coastal erosion or altered runoff — could reduce it.The paper identifies three major challenges to integrating polar blue carbon into policy. First, existing blue-carbon terminology and standards were developed for tropical and temperate coastal wetlands and do not readily capture the diversity of polar systems. Second, methods for measuring and accounting for carbon pathways are not yet sufficiently standardised, complicating comparisons between habitats and the assessment of additionality. Third, governance is fragmented: Antarctic waters are governed through the Antarctic Treaty System and CCAMLR, while the Arctic spans several national jurisdictions as well as areas beyond national jurisdiction — making coordinated, long-term protection difficult to achieve.Figure 1. Expected climate and ecosystem changes and uncertainties in polar environments and recommendations for better management and protection of these carbon rich habitats (Zwerschke, et al. (in press)).Around 10% of the world’s oceans are currently protected, and polar regions remain among the least protected of all. Against this backdrop, the authors argue that a precautionary approach could help protect relatively intact, carbon-rich and biodiverse habitats before increasing human pressures make them harder to conserve — providing climate and biodiversity benefits while scientific understanding continues to develop."This year we have experienced the impact of climate change dramatically across all temperate regions. The poles are on the forefront of this. Our governments need to take actions to curb climate change as well as protect natural systems that could help mitigate climate change. Protecting vulnerable polar systems and their immense carbon stores as part of an international effort would be a good start," states the first author of the article Nadescha Zwerschke.The review calls for four coordinated actions: greater investment in polar blue-carbon research; precautionary protection of known carbon-rich and vulnerable habitats; management approaches that consider carbon storage alongside biodiversity; and clearer pathways for recognising substantial natural carbon stores within policy frameworks. This does not mean polar blue carbon is ready to be treated as a conventional carbon-offset mechanism: significant uncertainties around measurement, additionality and permanence remain. In the near term, the review instead emphasises protecting existing carbon-rich ecosystems and strengthening the scientific and policy foundations needed for their future recognition.StudyZwerschke, N., Krause-Jensen, D., Barnes, D. K. A., Renaud, P. E., Austin, W. E. N., Ardyna, M., Attard, K., Bluhm, B. A., Comeau, S., Gattuso, J.-P., Hauck, J., Leu, E., Maar, M., Oziel, L., Poste, A. E., Schourup-Kristensen, V., Svensen, C., Thyrring, J., & Sejr, M. (2026). Status of Polar Blue Carbon: Toward Recognition and Integration in Marine Policy. Global Change Biology, 32(9), e71098. https://doi.org/10.1111/gcb.71098About POMPPOMP (Polar Ocean Mitigation Potential) is a Horizon Europe project studying how climate change affects biodiversity and carbon capture and storage in Arctic and Antarctic marine ecosystems. Coordinated by Aarhus University, POMP brings together 10 beneficiaries and 5 associated partners from Denmark, Norway, Germany, Greenland, France, Portugal, Canada and the UK, combining field data, ecosystem models and remote sensing to inform marine protected-area design and climate policy. POMP is funded by the European Union and, for UK-based partners, by UK Research and Innovation (UKRI).www.pomp-project.eu AcknowledgementsThis work was supported by the EU Horizon-funded POMP project (Grant No. 101136875) and by UK Research and Innovation (UKRI) for the project’s UK-based partners. Views and opinions expressed are those of the author(s) only and do not necessarily reflect those of the European Union or UKRI.For more information and/or interview requestsNadescha Zwerschke, lead author, Aarhus University, Department of Biology — nazw@bio.au.dkMikael Sejr, POMP coordinator, Aarhus University — mse@ecos.au.dk
