Global blue carbon accumulation in tidal wetlands increases with climate change

Faming Wang; Christian J Sanders; Isaac R Santos; Jianwu Tang; Mark Schuerch; Matthew L Kirwan; Robert E Kopp; Kai Zhu; Xiuzhen Li; Jiacan Yuan; Wenzhi Liu; Zhi'an Li

doi:10.1093/nsr/nwaa296

Global blue carbon accumulation in tidal wetlands increases with climate change

Natl Sci Rev. 2020 Dec 15;8(9):nwaa296. doi: 10.1093/nsr/nwaa296. eCollection 2021 Sep.

Authors

Faming Wang¹, Christian J Sanders², Isaac R Santos³, Jianwu Tang², Mark Schuerch⁴, Matthew L Kirwan⁵, Robert E Kopp⁶, Kai Zhu⁷, Xiuzhen Li², Jiacan Yuan⁶, Wenzhi Liu⁸, Zhi'an Li¹

Affiliations

¹ Xiaoliang Research Station for Tropical Coastal Ecosystems, Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, and the CAS Engineering Laboratory for Ecological Restoration of Island and Coastal Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China.
² State Key Laboratory of Estuarine and Coastal Research and Institute of Eco-Chongming, East China Normal University, Shanghai 201100, China.
³ National Marine Science Centre, School of Environment, Science and Engineering, Southern Cross University, Coffs Harbour NSW 2450, Australia.
⁴ Lincoln Centre for Water and Planetary Health, School of Geography, University of Lincoln, Lincoln LN67TS, UK.
⁵ Virginia Institute of Marine Science, College of William and Mary, Gloucester Point, VA 23185, USA.
⁶ Department of Earth and Planetary Sciences and Rutgers Institute of Earth, Ocean, and Atmospheric Sciences, Rutgers University, New Brunswick, NJ 08854, USA.
⁷ Department of Environmental Studies, University of California, Santa Cruz, CA 95064, USA.
⁸ Center of Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou 510650, China.

Abstract

Coastal tidal wetlands produce and accumulate significant amounts of organic carbon (C) that help to mitigate climate change. However, previous data limitations have prevented a robust evaluation of the global rates and mechanisms driving C accumulation. Here, we go beyond recent soil C stock estimates to reveal global tidal wetland C accumulation and predict changes under relative sea level rise, temperature and precipitation. We use data from literature study sites and our new observations spanning wide latitudinal gradients and 20 countries. Globally, tidal wetlands accumulate 53.65 (95%CI: 48.52-59.01) Tg C yr^-1, which is ∼30% of the organic C buried on the ocean floor. Modeling based on current climatic drivers and under projected emissions scenarios revealed a net increase in the global C accumulation by 2100. This rapid increase is driven by sea level rise in tidal marshes, and higher temperature and precipitation in mangroves. Countries with large areas of coastal wetlands, like Indonesia and Mexico, are more susceptible to tidal wetland C losses under climate change, while regions such as Australia, Brazil, the USA and China will experience a significant C accumulation increase under all projected scenarios.

Keywords: C burial rate; blue C; coastal wetlands; global change.