From 2 to 13 December 2019, the international community will meet for the 25th Conference of the Parties (COP25) to the UN Framework Convention on Climate Change (UNFCCC) in Madrid, Spain, under the Presidency of Chile. As with previous COPs, this will involve an intense international negotiations across a wide range of issues. However, there are two standout thematic issues for the parties at COP25: the ‘headline’ special focus on the world’s oceans at this so-called ‘blue-COP’, as promoted by the Chilean Presidency; and the now well-overdue completion of the Paris Rulebook – the common principles needed to give technical and operative effect to the Paris Agreement – which has suffered from a lack of agreement on cooperative frameworks for climate action under Article 6. To that end, the parties should look to the Southern Ocean and the vast, expanding, Antarctic ‘blue carbon’ sinks in that area. These sinks should be important to frame discussions on a non-market cooperative approaches to climate mitigation within the theme focus of oceans and the cryosphere.

What is Antarctic Blue Carbon?
Blue carbon refers to carbon sequestered from the atmosphere into marine ecosystems around the planet. The largest sites of blue carbon are found in the Southern Ocean, which, unlike blue carbon in vegetated coastal ecosystems (i.e. mangroves, tidal marshes and seagrass meadows) are expanding as a result of climate change. Polar sea ice, glaciers and ice-shelves are relative deserts. As they melt, they are replaced by open ocean which takes up more carbon dioxide than ice, into which an ecosystem
colonises. These ecosystems may eventually draw down carbon dioxide from the atmosphere and sequester it into ocean sediments.

At a conservative estimate, Antarctic blue carbon sites are expected to store up to 160,000,000 tonnes of carbon annually. In fact, properly protected and promoted blue carbon sites could serve as the world’s largest natural negative feedbacks on climate change. At present, our understanding of the productivity, standing stock and drivers of blue carbon sinks is not matched by an equivalent understanding of the threats to these sites, especially from human activities. Given carbon sequestration will take tens to hundreds of years to occur, a precautionary, whole of ecosystem approach is warranted for their protection. However, implementing conservation measures for these ecosystems will be challenging, not least because of the territorial and legal character of Antarctica.

Co-operative approaches to Blue Carbon conservation
Antarctic blue carbon is located within a globally unique space – one where claims of state sovereignty have been put ‘on hold’ under the provisions of the Antarctic Treaty System (ATS). The ATS is a regime for the cooperative international management and conservation of areas south of 60S. The parties, including (arguably especially) the ones with territorial claims to Antarctica, are sensitive to avoid acts which would upset the diplomatic compromise underlying the ATS. This would include interests in carbon stocks contained in blue carbon sinks around Antarctic coastline as part of their Nationally Determined Contributions (NDCs) to emission reduction goals under the Paris Agreement. On the other hand, the ATS, and the cooperative governance arrangements align directly with the broad cooperative climate action framework of Article 6 of Paris. That is, states may not be willing to individually account for Antarctic blue carbon under Paris, but that Agreement encourages them to cooperatively do so, in a non-market ‘integrated, holistic and balanced’ manner “across instruments and relevant institutional arrangements” (Art 6.8-6.9).

In our paper, we suggest the development of a non-market platform that connects the UNFCCC Paris Agreement to the ATS to allow for the collective carbon accounting and attribution of the carbon stocks of the Southern Ocean. This will have the additional benefit of incentivising the protection of Antarctic marine ecosystems; a conservation process which, itself, has faced diplomatic obstacles from ATS states which view such measures as contrary to their national interests. Given blue-carbon sites are in areas where biodiversity and biomass will increase, commercial interests and pressures may arise in the future. By providing an incentive to conservation, the balance might be tipped from commercialisation to conservation of these important carbon sinks. While clearly much work will need to be done in developing this on-market platform, the Paris Agreement, by its nature encourages iterative and reflective processes of cooperation on climate change. This would allow a blue carbon non-market approach to be constructed over time, as our scientific knowledge develops. The Blue COP seems the right place to start this iterative process, and in so doing advance the progress of the Paris Agreement more generally.

The paper, Protecting Antarctic blue carbon: as marine ice retreats, can the law fill the gap? is available to read as part of the Climate Policy: Editor’s Choice collection

Brendan Gogarty is a lawyer and legal scholar specialising in public and international law.

Rachel Downey is a specialist in a polar and deep-sea sponge taxonomy, benthic biogeography, and threats to polar sea bed habitats.

David Barnes is a Benthic Ecologist at the British Antarctic Survey, researching the interactions between benthos and their environment on continental shelves in polar and remote
island regions.

Jeff McGee researches on climate change, oceans and Antarctic law at the Faculty of Law and Institute for Marine and Antarctic Studies at the University of Tasmania.

Chester Sands is a Molecular Ecologist at the British Antarctic Survey focusing on resilience of populations and assemblages and the ecosystem services they provide.