Sunday, September 27th, 2026
By Miguel Leal
A review published recently in Global Change Biology assesses how far Arctic and Antarctic marine ecosystems could be incorporated into the frameworks used to address climate change and protect biodiversity. Led by Nadescha Zwerschke (Aarhus University) with an international POMP author team, it questions which polar habitats could be managed for their carbon-storage benefits, and what is keeping them out of policy.
The Arctic and Antarctic represent around 20% of the global ocean, and parts of the Arctic are warming at up to four times the global average rate. As sea ice retreats, the ways polar ecosystems capture, transport and store carbon are changing too. Yet blue carbon approaches were developed around tropical and temperate coastal wetlands, and polar systems remain largely unrecognised within them.
The review groups polar blue carbon into three categories. Arctic salt marshes and seagrass meadows have relatively strong evidence for their carbon-storage potential. Kelp and other macroalgae 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. Least understood are phytoplankton, microphytobenthos and ice-associated algae, and carbon stored in fjord, shelf and deep-sea sediments. For most, estimates of extent, stocks and long-term sequestration remain limited, and the direction of future change is unclear: some processes could increase carbon uptake, while coastal erosion or altered runoff could reduce it.
Three obstacles stand in the way of policy integration: blue carbon terminology and standards developed for other ecosystems, measurement and accounting methods that are not yet standardised, and fragmented governance. Antarctic waters are managed through the Antarctic Treaty System and CCAMLR, while the Arctic spans several national jurisdictions as well as areas beyond them.
Around 10% of the world’s oceans are protected, and polar regions remain among the least protected. The authors call for more investment in polar blue carbon research, precautionary protection of carbon-rich and vulnerable habitats, management that weighs carbon alongside biodiversity, and clearer pathways for recognising natural carbon stores in policy. Uncertainties around measurement, additionality and permanence still keep polar blue carbon from working as a conventional offset.
Read the full review Global Change Biology.