FAQ

The ocean currently stores massive amounts of CO₂, keeping atmospheric concentrations lower than they would otherwise be. Marine organisms (plankton, microbes, fish, and other marine life) play a role in that storage.

Emerging evidence suggests that most existing climate and earth system models underrepresent or simplify these biological impacts, especially understanding how marine life affects the ability of the ocean to absorb CO2 from the atmosphere, how much CO₂ is converted into living material, and where in the ocean that organic carbon eventually converts back to CO₂.

This underrepresentation introduces substantial uncertainty into estimates of the how marine life helps the ocean store carbon and how that capacity may change under global warming. 

We know that atmospheric carbon dioxide has fluctuated in the past through shifts in ocean biology. People are considering deliberate interventions to encourage marine life to take up more carbon as a form of climate mitigation called marine carbon dioxide removal (mCDR).

By filling gaps in our knowledge with new data and better parameterisations, BIO-Carbon will enhance next generation models, reducing uncertainty in ocean carbon storage forecasts and improving projections of future scenarios.

• Many models used to predict global carbon stocks and future climate poorly represent biological processes.
• Some marine organisms can influence how well seawater absorbs carbon dioxide from the atmosphere, but we don’t know how significant this is.
• There is uncertainty in the rate at which marine organisms first convert carbon dioxide into living material, organic carbon.
• Many processes involving the transfer of the organic carbon through the ecosystem, such as one organism eating another, are poorly understood.
• There is also uncertainty on where within the ocean the organic carbon is eventually turned back into carbon dioxide by organisms respiring or decaying.

Consequences of these limitations:

• High uncertainty in whether the use of carbon by ocean life is increasing or decreasing under climate change.
• Difficulty in predicting how climate change will impact ocean carbon storage by marine life.

BIO-Carbon addresses these gaps by gaining a better understanding of‑ the effects of marine biology on carbon storage.

BIO-Carbon aims to tackle three major challenges related to the biological influence on ocean carbon storage.

How does marine life affect the potential for seawater to absorb CO₂, and how might that change?

The ocean’s capacity to absorb CO₂ depends on seawater alkalinity, which is influenced by biological processes such as the creation and dissolution of calcium carbonate (a mineral like chalk) by organisms. But there are many uncertainties in global estimates of these processes, leading to large uncertainty in our ability to model current or future ocean alkalinity.

How will the rate at which marine life converts dissolved CO₂ into organic carbon change?

Marine phytoplankton (and other organisms) take up CO₂ via primary production (photosynthesis), converting it into organic matter. Climate change may change factors that affect this process (light, nutrient supply, temperature, stratification), but we don’t know whether the combined effect we will see an increase or decrease in the critical process of primary production.

How will climate-driven changes in ecosystem respiration affect future ocean carbon storage?

Respiration by marine organisms (microbes, zooplankton, fish, etc.) converts organic carbon back into CO₂, which may be released back to the atmosphere or remain in the ocean. The rates and controls of respiration, and how they vary with depth, ocean region, temperature, oxygen, season, are poorly constrained. Changes in respiration under warming could significantly alter net carbon storage.

BIO-Carbon employs a multi-pronged, interdisciplinary strategy combining observations, modelling, and community building. Key components include:

• New datasets and field campaigns including use of research vessels and a variety of autonomous vehicles (e.g. Boaty McBoatface) to sample open-ocean waters with a focus in the deep waters (>1000m) beyond continental shelves and on processes that are globally relevant.
• Laboratory, field data analysis and modelling work to develop new ways to represent biological processes (e.g. carbonate production/dissolution, respiration, organic carbon production) in models used to estimate global distributions of carbon.
• Integration into global models. The final stage of BIO-Carbon will see the new biological parameterisations implemented into a suite of global models to make more robust predictions for how climate change may impact biological ocean carbon storage.
• Community building through the Early Career Ocean Professionals (ECOP) network. Bringing together early-career researchers working on different aspects of ocean biology and carbon, facilitating collaboration, knowledge exchange, skill building, development and outreach.

• Conducting lab experiments under different temperature, nutrient, and light scenarios.
• Using regional differences in the open ocean as proxies for different temperatures and conditions.
• Using model simulations to project future impacts on carbon storage.

All but a tiny fraction of the carbon converted into living material (that is trapped in sediment on the seafloor) is eventually respired back to CO2 within the ocean. The depth at which this happens controls how long the CO2 is away from the atmosphere. Many, poorly understood interactions in the marine ecosystem influence this depth. There are regions of the ocean deep where CO2 may remain trapped for over hundreds of years. We don’t understand how climate change will affect this though, by affecting the ecosystem processes that control it.

• The whole programme is funded by the Natural Environment Research Council (NERC).
• Stage 2 of the programme will be jointly funded by NASA.
• The projects already involve many UK and international partners, including:

UK partners

• British Antarctic Survey
• Heriot-Watt University
• Imperial College London
• National Oceanography Centre
• Plymouth Marine Laboratory
• University of East Anglia
• University of Exeter
• University of Liverpool
• University of Oxford
• University of Plymouth
• University of Southampton
• University of Strathclyde
• Chelsea Technologies
• Inshore Fisheries and Conservation Authority
• Marine Biological Association
• National Marine Aquarium
• University of Aberdeen

International Partners:

• AORI, Japan
• AWI, Germany
• Bigelow Laboratory, USA
• BIOS, Bermuda
• CEI, Bahamas
• CSIC, Spain
• CSIR, South Africa
• Dalhousie University, Canada
• Geomar, Germany
• Goethe University, Germany
• Ifremer, France
• IMO, Chile
• ISP, Italy
• LCSE, France
• LOCEAN, France
• LOV, France
• MFRI, Iceland
• MIO, France
• OGS, Italy
• Oregon State University, USA
• Scripps Institution of Oceanography, USA
• Sorbonne University, France
• Texas A&M University, USA
• Thunen, Germany
• ULPGC, Spain
• University of Delaware, USA
• University of Ghent, Belgium
• University of Antofagasta,Chile University of Oslo, Norway
• University of Vienna, Austria
• UTAS, Australia
• Virginia Institute of Marine Science, USA

• Stage 1 (2022–2026): 9 projects involving field campaigns, lab studies, and preliminary modelling
• Stage 2 (2026–2028): Model integration, projections to 2100, policy-relevant outputs.
• In stage one, the programme carries out observational, laboratory, and modelling studies to improve mechanistic understanding of biological processes affecting ocean carbon storage.
• In stage two, novel modelling approaches will be developed, and new parameterisations will be implemented into a range of global models to assess the impact of biologically mediated changes to ocean carbon storage to 2100, including sensitivity to environmental change.
• Expected outputs: new globally relevant datasets, improved understanding of key processes, and more robust projections of ocean carbon storage under climate change. This will ultimately inform policy, climate mitigation targets, and contribute to major assessments (e.g. by IPCC).

The BIO-Carbon ECOP (Early Career Ocean Professionals) network has been developed to achieve this. Through this network, BIO-Carbon:

• Connects early-career researchers working on biological ocean carbon storage from different disciplines and institutions.
• Offers peer-to-peer skill-sharing, and networking opportunities.
• Encourages collaboration across projects, sharing of data and ideas, helping build a sustainable research community around ocean biological carbon processes.

Key References and Resources:

• BIO-‑Carbon Official Website
• NERC BIO-‑Carbon Funding Page
• BIO-‑Carbon ECOP Network
• BIO-‑Carbon Projects