Editorial for the special issue on marine carbon sequestration and climate change
Nianzhi Jiao1, Zhengtang Guo2, Louis Legendre3, Curtis Suttle4, Richard Rivkin5,and Farooq Azam6
In the 1980s, the realization that the ocean was potentially a major sink of atmospheric CO2 stimulated the international research community under the auspices of the Scientific Committee ofOceanicResearch (SCOR),International Council for Sci- ence (ICSU), to launch the multidisciplinary research program Joint Global Ocean Flux Study. Since then, the understanding ofthe biological, ecological, chemical and physical processes underlying the ocean carbon cycle and the ability to predict its sen- sitivity to global change have increased enormously. One piece of significant progress from the above international joint ef- forts is the understanding of the biological mechanism of ocean carbon sequestration known as the Biological Carbon Pump (BCP), which depends on the vertical transport of organic matter from surface waters to the deep ocean and the seabed. How- ever, the BCP does not address the following enigma,whichwas proposed halfacentury ago: what were the formation mechanisms of the huge pool of refractory dissolved organic carbon(RDOC) in the ocean, which has an amount of carbon equivalent to the total inventory of atmospheric CO2 and an average estimated residence time of 5000 years?
Recently, the recognition of a microbial carbon sequestra- tion mechanism, the Microbial Carbon Pump (MCP), shed light on the enigma. The MCP operates independently of depth, as it depends on the microbial transformation of organic matter to RDOC, thus sequestering carbon throughout the water column. A working group under SCOR (2008–14) made significant progress in the MCP framework, followed by numerous studies with intriguing insights. Giventhe pressing need for knowledge on climate change and its regulation mechanisms, a joint working group was estab- lished under the auspices of the North Pacific Marine Sci- ence Organization (PICES) and the International Committee for Exploration of the Sea (ICES) in 2015 (WG 33 forPICES and WGCCBOCS for ICES) on the theme of cli- mate change and the biologically driven ocean carbon sequestration. This theme was selected as the topic of the 1stYanqi Lake Meeting (YLM)—a new international forum ini- tiated by the Chinese Academy of Sciences (CAS) as a world-class platformfor brainstorming atthe frontiers ofscience and technological innovation.
The 1st YLM was held on 19–22 September 2017, at the Yanqi Lake Convention Center, Beijing, co-chaired by five academicians from China, Canada, Europe and the USA. Leaders from CAS, the Ministry of Science and Technology of China, the State Ocean Administration of China and the Intergovernmental Ocean Commission of UNESCO deliveredaddresses at the opening ceremony. Members of the PICESICES joint WG and 30 Chinese scholars and CAS members held in-depth discussions on various aspects of the MCP andthe BCP. The editors of National Science Review (NSR) attended the 1st YLM, and invited six articles forming the present special issue:
- A Highlight on aChinese research project on the MCP,whose outcomes are considered to have profound implications for the understanding of biologically driven ocean carbon storage.
- APerspective paperthattacklesthe RDOC enigma in the MCP framework at both microscales (cellular, enzymatic and genetic) and macroscales (observation of microbial transforma- tions of organic carbon in the field and under manipulated ex- perimental conditions).
- A Perspective paper about blue carbon, which convention- ally referred to coastal rooted plants and now includes the open-ocean carbon sequestered by the BCP and the MCP, whose amounts are much more significant at the global scale.
- A Perspective paper that proposes an implementation strategy to quantify the MCP and its sensitivity to global change,suggesting that the analytical tools and intellectual interaction between chemists and microbiologists are now at a stage where the societally driven question of marine carbon storage can, and must, become a high-priority researchtopic.
- A Perspective paper that proposes a modelling framework describing the formation of RDOC through the MCP. The proposed formulation only uses two state variables and can be integrated in biogeochemical/ecosystem models with different levels of complexity.
- AReviewpaper on evolving paradigmsin biological carbon cycling in the ocean, examining the MCP concept from theoretical and practical points of view with related concepts including the BCP, the Microbial Loop (ML) and the Virus Shunt (VS). The review highlights the importance of the MCP sup- ported by data from advanced ‘omics’ and its inspiration of novel research, and advocates integrated approaches to promote future research on the MCP and its integration with the BCP, ML and VS.
This special issue is a collection of up-to-date syntheses on biological ocean carbon sequestration mechanisms and their relations with climate change. The MCP paradigm is shap ing a new direction in ocean carbon-cycle research. Papers in this topic provide a benchmark for researchers and policy makers.
Nianzhi Jiao1,*, Zhengtang Guo2, Louis Legendre3, Curtis Suttle4,5, and Farooq Azam6
1Xiamen University, China
2Institute of Geology and Geophysics, Chinese Academy of Sciences, China
3Laboratoire d’Oceanographie de Villefranche, France
4University of British Columbia, Canada
5Memorial University of Newfoundland, Canada
6University of California San Diego, USA
Corresponding author. E-mail: jiao@xmu.edu.cn
Guest Editor of Special Topic
Section Editor for Earth Sciences at NSR