The ocean stores huge amounts of carbon dioxide (CO2) that would otherwise be in the atmosphere.
Marine organisms play a critical role in this process, but emerging evidence indicates that climate models are not fully accounting for their impact.
This undermines carbon policies, such as national net zero targets.
This biological influence on future ocean storage of carbon (BIO-Carbon) research programme is carefully designed to produce new understanding of biological processes. It will provide robust predictions of future ocean carbon storage in a changing climate.
The World Climate Research Programme (WCRP), which coordinates climate research internationally and is sponsored by UN organisations, has expressed its greatest priorities as three questions.
This programme will address two of those questions:
- what biological and abiological processes drive and control ocean carbon storage?
- can and will climate-carbon feedbacks amplify climate changes over the 21st century?
There are three interlinked programme challenges, which will address three aspects of biological influence:
Challenge one: how does marine life affect the potential for seawater to absorb CO2, and how will this change?
The ability of the ocean to absorb CO2 is influenced by its alkalinity. Reducing alkalinity pushes more of the dissolved carbon in seawater into the form of CO2.
This reduces the capacity of the ocean to take up further CO2 from the atmosphere.
Seawater alkalinity is influenced by a range of natural processes. The most important of these is the biological production of calcium carbonate (for example, by molluscs and fish), which removes alkalinity from seawater.
As the calcium carbonate sinks, it dissolves and the alkalinity is returned to the seawater.
Maintaining the vertical distribution of alkalinity fundamentally sets the capacity of our oceans to take up CO2. However, estimates of global ocean calcium carbonate production, vertical transport and dissolution vary by up to a factor of five.
This uncertainty is important because failure to reproduce alkalinity accurately in a climate model significantly impacts future projections of ocean CO2 uptake and storage.
Examples of significant knowledge gaps relating to key processes include:
- what organisms are producing highly soluble carbonates in the surface ocean, and where?
- which forms of calcium carbonate are dissolving where in the ocean?
- what are the factors involved in the dissolution of different forms of carbonate, and what is their sensitivity to the anticipated impacts of climate change?
Challenge two: how will the rate at which marine life converts dissolved CO2 into organic carbon change?
Primary production by marine phytoplankton converts a similar amount of CO2 into organic material each year as do all land plants combined.
Climate models cannot constrain this crucial global flux to within a factor of three for the contemporary climate, which points to major gaps in understanding.
Furthermore, uncertainty about our estimates for how oceanic primary production will change under climate warming has increased, rather than lessened, this decade. Whether global primary production will increase or decrease is unknown.
Primary production is strongly influenced by ocean warming and the availability of light and nutrients. However, the contributions of changes in these drivers to trends across climate models are poorly constrained.
The importance of organism interactions and metabolism, and their associated demands for carbon and other resources, is neglected by climate models. This is despite emerging observational indications of their significance.
Examples of knowledge gaps relating to key processes, operating across different scales, include:
- what controls the efficiency of primary production?
- what are the contributions of nutrient recycling and the consumption of phytoplankton by zooplankton to this efficiency?
- how do these processes vary across different ocean environments, and how might future change, such as warming and acidification, affect them?
Challenge three: how will climate change-induced shifts in respiration by the marine ecosystem affect the future ocean storage of carbon?
Organic carbon produced in the upper ocean cannot be returned to the atmosphere until it is converted back into CO2 by the respiration of marine organisms.
Deeper ocean respiration supports longer carbon storage as it takes longer to return to the ocean surface and make contact with the atmosphere.
We still have poor understanding of how respiration varies with depth, location or season. We know it reflects the diversity of the organisms, from bacteria attached to sinking dead material to fish migrating daily between the surface and the ocean interior.
We also know that these organisms are responding to anthropogenic changes, such as changes in temperature which affect the metabolism of organisms.
In addition, existing models only reproduce a limited selection of relevant processes, with no consistency in that selection across models.
Examples of significant knowledge gaps relating to key processes include:
- what is the relative influence of size, shape and composition of non-living organic material in determining the rate at which it is converted back to CO2?
- what are the relative magnitudes of the CO2 generated by bacterial degradation of non-living organic matter and that respired directly by other organisms?
- how might ongoing changes in the environment (for example, to oxygen or temperature) affect respiration?
Aims
In addressing challenges one, two and three, research will provide a fundamental understanding of key biological processes that are globally relevant.
By encapsulating this new knowledge in a robust modelling framework, it will examine the resulting feedback on future predictions for how global ocean carbon storage may change.
Additionally, it will provide new parameterisations of key processes for inclusion in the next generation of climate models, and ‘emergent constraints’ to identify clearly erroneous forecasts.
The use of emergent constraints has been successfully applied to other areas of climate science, such as a constraint on climate sensitivity provided by air temperature variability or cloud feedbacks. However, it is yet to be adopted widely in marine science.
Geographic focus
The BIO-Carbon programme aims to highlight the importance of international waters to discussions on carbon policy.
All BIO-Carbon projects are therefore required to focus research on processes that are globally relevant, in waters:
- within the open ocean water column that regulate carbon storage
- beyond the continental shelf break
- where the seafloor is typically at a depth greater than 1,000m.
BIO-Carbon fieldwork projects, which will be funded through a future opportunity, will be focused in the North Atlantic.
This is where the programme’s resources can be most effectively mobilised, and is a region where the relevant processes can be studied.
Outcomes
The outcomes of this research programme will:
- enhance our understanding of key biological processes that affect how carbon storage by the global ocean will change in the future
- significantly improve global ocean carbon budget projections, to better inform policy development and decision making in support of net zero ambitions
- provide new parameterisations of key processes and emergent constraints on global model behaviour for use in simulations feeding into the Intergovernmental Panel on Climate Change’s (IPCC) seventh assessment report
- implement new parameterisations and constraints in a suite of global models in order to provide a robust assessment to 2100 of the biologically associated changes in global ocean carbon storage, and their sensitivity to key processes identified by this programme. This assessment should be suitable for inclusion in IPCC’s seventh assessment report
- provide a significant UK contribution to the UN Ocean Decade outcome for ‘a predicted ocean’ by improving our ability to model oceanic responses under anthropogenic influence
- address two priorities of the WCRP’s grand challenge on carbon feedbacks in the climate system.
Funding
Apply for funding to take on the role of programme champion for the BIO-Carbon programme.
The champion will lead on supporting implementation of the programme, working closely with the BIO-Carbon Programme Advisory Group (see the ‘delivery and coordination’ section) and NERC.
Key tasks
You will lead on managing integration between projects within the research programme.
You will lead on and organise programme meetings and workshops to ensure that the knowledge generated by projects is shared to help realise programme outcomes. This includes two key workshops:
- the first in March 2023, to inform the community of the outputs of stage one modelling and laboratory and gap analysis projects (see the ‘additional information’ section), ahead of the release of a funding opportunity for fieldwork proposals
- the second in summer 2025, to inform the community of the final outputs of stage one modelling and laboratory and gap analysis projects, and the latest findings of the fieldwork projects, ahead of the release of the funding opportunity for modelling proposals.
You will support the Programme Advisory Group in developing a well-evidenced recommendation for NERC on the programme’s cruise plan, which will be included in the fieldwork funding opportunity.
This includes leading the planned community workshop.
You will proactively engage with the national and international community to ensure that the BIO-Carbon programme has strong links and synergies with other relevant research programmes and initiatives.
These might include the NERC-funded national capability BIOPOLE programme, and the United Nations Decade of Ocean Science for Sustainable Development.
You will lead on the communication strategy for the programme.
You will support programme management as required by NERC.
This includes leading on project monitoring and programme-level reporting, and ensuring appropriate evaluation and monitoring procedures are in place for the programme.
You will lead on ensuring that all the programme’s commissioning and delivery risks are identified at the earliest opportunity, and that appropriate risk mitigation plans are put in place.
You will lead on the data management strategy for the programme.
The programme champion role can be carried out by an individual, or by a small group of individuals with an identified lead.
Those named on the champion grant will not be eligible for any of the other funding opportunities that form part of this research programme.
The champion role is for 68 months. You must start no later than 3 August 2022.
The full economic cost of the champion grant can be up to £575,000. NERC will fund 80% of the full economic cost.
