• PICES Acronym: WG 46 (ONCE)
• Parent Committees: BIO, POC
  
• Term: PICES-2020 - PICES-2023
• Disbanded: IGC-2024
• Final Report
• PICES Co-Chair: Prof. Nianzhi Jiao (<jiao@xmu.edu.cn>)
  PICES Co-Chair: Prof. Douglas W Wallace (<Douglas.Wallace@dal.ca>)
  ICES Co-Chair: Dr. Louis Legendre (ICES/France, <legendre@obs-vlfr.fr>)
  ICES Co-Chair: Dr. Carol Robinson (ICES/UK, <carol.robinson@uea.ac.uk>)

Negative carbon emissions is an approach to the goal of the Paris Agreement to limit global warming to 2.0° or perhaps even 1.5°C by the end of this century. The ocean has a large capacity to sequester carbon and has absorbed approximately 25% of the CO2 produced by fossil fuel combustion and cement production since the beginning of the industrial revolution. Ocean Negative Carbon Emission (ONCE) has the potential to contribute to negative emissions if the mechanisms and processes involved are properly understood.

The majority of the organic carbon in the ocean is in the form of dissolved organic matter (DOM), which contains an amount of carbon equivalent to the total inventory of atmospheric CO2 and whose refractory component is a form of sequestered carbon in the ocean. The previous PICES/ICES joint WG-33 on “Climate Change and Biologically-driven Ocean Carbon Sequestration” highlighted the importance of microbial processes in the production of refractory DOM in the ocean, and identified a potential ONCE technique based on the naturally occurring microbial carbon pump. However, there is a gap between this natural process and its potential application. In addition, our knowledge of other ocean carbon sequestration mechanisms and processes, such as the solubility pump, carbonate pump and the different components of the biological carbon pump, limit their potential application for mitigating climate change.

The proposed new PICES/ICES joint Working Group will promote interdisciplinary exchange among different research communities by bringing together experts with backgrounds in science (biological, biogeochemical, chemical and physical oceanography) and engineering, to develop theoretical bases, provide guidelines, and evaluate the implementation of ONCE. The activities of the proposed WG will receive strong financial support from Xiamen University, China, and more funding is currently being sought from other Chinese sources. The WG members will use data from coastal and open ocean time- series and macrocosm facilities to assess proposed ocean negative carbon emission models. The WG has the long-term objective of providing advice for climate policy and practical implementation of ONCE for the scientific community, the public and governments.

The main objectives of this WG are to:

• identify current knowledge gaps in negative carbon emission in the oceans; and,
• propose future research directions and applications to the enhancement of negative carbon emissions including the items below:
  • Developing additional long-term time series stations to observe carbon sequestration in representative coastal and offshore waters;
  • Proposing integrated experimental studies to better understand carbon sequestration under paleo-, current and future oceanic conditions;
  • Proposing an international collaborative project or program dedicated to ocean negative carbon emission;

• Publish reviews, special sections and/or research papers to summarize and/or analyze the mechanisms and processes of negative carbon emission in the ocean;
• Proposal for future research directions of negative carbon emissions;
• Create a brief, clear, concise outreach product to communicate WG findings to a broader audience, especially the general public;
• Produce a final report summarizing the results of the WG.