Blue carbon – climate change and ecosystem services

By Sian Rees and Holly Niner

The ocean is integral to the delivery of global processes that regulate the climate and enable humanity to thrive (and in fact protect basic human rights). At COP26 in November 2021, the ocean was officially integrated into all areas of work at the UN Framework Convention on Climate Change (UNFCCC) for the first time, but how this should be done (both scientifically and administratively) remains outstanding and will be discussed at COP27 in Egypt next week. This blog post outlines the growing demand for blue carbon and the current status of scientific knowledge to support the use of the concept as a ‘nature-based solution’ to climate change. We begin by describing the current gaps in knowledge for the operationalisation of blue carbon, potential options for management and how our work as part of the One Ocean Hub is supporting the development of governance that could support blue carbon as a solution for climate change.

Key open questions

The ocean hosts a major proportion of the world’s biodiversity valued for the innumerable range of ecosystem services (benefits to people) it provides. Biodiversity, through imparting resilience, can act as an insurance policy against ecosystem service loss driven by climatic changes. However, biodiversity suffers degradation as it comes under pressure from climate change, and so does this resilience. Accordingly, ‘climate responsive’ governance of the ocean is becoming increasingly important.

The protection, restoration, enhancement and creation of blue carbon ecosystems have been proposed as an option or ‘solution’ for nations to meet their carbon management. Blue carbon refers to carbon converted into organic carbon and stored in marine ecosystems such as saltmarsh, seagrass or kelp habitats. Blue carbon is emerging as a driver for the protection of critical ecosystems with evidence developing of a link between projects and regional economic development as the concept attaches the potential for a quantifiable ‘value’ to natural assets. There are, however, various challenges to the effective operationalisation of the blue carbon concept:

  • While the majority of marine habitats have a role to play in the carbon cycle, only three have international guidelines for inclusion in national greenhouse gas inventories – saltmarsh, seagrass and mangroves – by the Intergovernmental Panel on Climate Change.
  • The institutional governance for blue carbon ‘markets’ is not available and with many projects only financially viable at scale, the setting is complex likely crossing different marine areas under different forms of jurisdiction.
  • Further complexity is introduced where the rights to a property do not clearly convey the right to sell carbon or when legal frameworks conflict with the claims of a local community or users which may be affected by the development of a blue carbon project. As blue carbon governance progresses an important component will be to ensure that projects are delivering on stated aims such as community co-benefit.
Illustration by Margherita Brunori

Learning from marine protected areas

In recognition of the importance of blue carbon ecosystems for critical ecosystem services and the increasing threats posed by accelerating climate change, there is a strong impetus for research to meet the demands of blue carbon inventory operationalisation and it is moving fast to fill the gaps. In the absence of experience and knowledge specific to blue carbon and acknowledging the urgency of the situation, we can lean on successful models for habitat creation, protection and restoration taking place in marine protected areas (MPAs).

  • Adoption of target for 30% MPAs for blue carbon assets (in addition to the conservation features). While MPAs are currently the main policy tool to protect biodiversity, given that carbon is stored across the majority of marine ecosystems, they may not be sufficient on their own as a vehicle to protect blue carbon assets. In recognition of this, an ambitious shift in policy is needed to centre blue carbon assets as the primary focus for sustainable management both within and outside of MPAs.
  • Application of a “whole site” approach to MPA management. Such an approach applies uniform management measures, to remove destructive activities entirely (such as trawling), across an MPA as opposed to varying across habitat type within an MPA leaving most of the area still vulnerable to disturbance. A whole site approach has been demonstrated to support widespread habitat recovery and creation.

Other modes of blue carbon governance

Beyond MPAs, marine ecosystem management for blue carbon will need to move to climate-responsive marine spatial planning (MSP), which will involve managing ‘pressures’ exerted on the environment. Recognising that for many marine areas, and therefore blue carbon assets, information to quantify the ‘amount’ of stored carbon in a particular site is limited. Other data constraints relate to information describing the pressures on blue carbon assets. Combined, this challenges traditional risk assessment approaches and foregrounds the need for a risk-based approach to management, such as through a natural capital risk register. For example, in lieu of evidence to quantify blue carbon potential, MSP could apply a proxy target for asset management such as ‘areas of the seabed closed to benthic towed gear’ where blue carbon asset ‘value’ increases with time as an area is allowed to recover.

Our research

As part of the One Ocean Hub, the University of Plymouth has applied the natural capital approach to areas beyond national jurisdiction (ABNJ) – the high seas and the deep seabed. In our forthcoming analysis, we highlight societal links to these areas and the global implications of any degradation in ecosystem services as the ocean warms, deoxygenates and acidifies. We show that while the global ocean’s capacity to store carbon is fundamental for thriving societies and yet is imperilled by activities that benefit corporate interests, that are not governed in respect of their impacts on diffuse benefit flows to society from the ocean. Our interdisciplinary study based on a natural capital approach includes the creation of habitat maps, the development of a framework to capture and describe deep-sea ecosystem services and an analysis of the ways that people are connected to the region. Together with colleagues from across the Hub, we then consider that these benefit flows underpin basic human rights, such as that to health, food, and culture, and that cumulative management centred on ecosystem resilience is imperative. In support of management of these critical benefit flows from data-poor regions of the ocean, we are piloting an approach that makes ecosystem services and human connection to these environments ‘visible’ within decision-making.

COP27 Virtual Ocean Pavillion: Climate Change and Ecosystem Services in Areas Beyond National Jurisdiction. November 16th 12:00-1:30PM GMT