Program uses Singapore Time and is 8 hours ahead of GMT

Axford Medal Lecture/Live Q&A Thu-04 Aug 16:00 – 17:00

Ocean Carbon Cycle and Ocean-Based Carbon Dioxide Removal

The injection of anthropogenic CO₂ into the atmosphere and its subsequent distribution across the ocean, land, and atmosphere components of the Earth system have led to an unprecedented perturbation of the global carbon cycle that has been ongoing since the Industrial Revolution. The ocean, a sustained sink for anthropogenic CO₂ released into the atmosphere by fossil fuel burning over the last ~ 150 years, has been altered by this CO₂ uptake and the effects of this perturbation are evident in the world ocean. The complexities of the land-ocean-atmosphere coupled system introduce large uncertainties into projections of ocean carbon fluxes, which is of fundamental importance to climate science and climate policies developed before and after the achievement of net zero CO₂ emissions (i.e. carbon neutrality).

The adoption and implementation of the actions proposed by many countries in the Paris Agreement introduces another set of perturbations to the Earth system on decadal time scales. Continued emission growth, followed by the transition from peak to net zero emissions in the mid-21st century, will be superimposed on changes that have already occurred throughout the industrial era. Confounding this adjustment to emissions are intended carbon dioxide removal activities (CDR, e.g. artificial ocean alkalinization) and ecosystem restoration (e.g. mangrove forest restoration) that are planned or already underway. The combination of these activities will again affect the global carbon cycle by producing abrupt CO₂ redistribution within the Earth system, including at the land-ocean interface. Understanding the response of the ocean carbon sink to these perturbations, individually and collectively, is a major challenge that has implications for the overall global carbon budget and the carbon-climate coupled system.

My presentation begins with the current understanding of the ocean carbon cycle with a special focus on the coastal ocean, aimed at identifying the remaining critical knowledge gaps in understanding and quantifying carbon fluxes and underlying controls. These include internal process interactions, responses to external and boundary forcings, and responses to human-induced local and global perturbations. I will then introduce a wide array of potential ocean-based mitigation options that can contribute to carbon neutrality goals. I emphasize that a healthy marine ecosystem is a prerequisite to enable efficient and beneficial utilization of these ocean-based carbon-goal opportunities. Here, ecosystem-based integrated ocean management (EB-IOM) serves as an efficient instrument.

Minhan Dai was born in Hangzhou, China in 1965 and received his Bachelor degree in ocean science from Xiamen University. Subsequently, he studied for his Doctorate in Earth Science at University of Pierre & Marie Curie and graduated in 1995. He was awarded the Woods Hole Oceanographic Institution (WHOI) Doherty Foundation Postdoctoral Fellowship in 1995. Upon completing his postdoctoral research at WHOI, he joined Xiamen University in 1998 as a faculty member and has remained with the university ever since.

He is currently a Chair Professor of marine biogeochemistry at Xiamen University, China, where he served as the Director of the State Key Laboratory of Marine Environmental Science between 2005-2021. He was elected an Academician of the Chinese Academy of Sciences in 2017.

His primary research interests include ocean biogeochemistry and its coupling with ocean dynamics. He is also well known for his work on marine radiochemistry. Recently, his research scope has expanded to linking ocean science and sustainability. He has published over 200 peer-reviewed papers in leading international journals including Science, Nature Geoscience/Climate Change/Ecology & Evolution/Communication

Minhan Dai has been a member of AOGS since 2007. He served as Vice President/President of the Ocean Section during 2008-2009/2009-2010, respectively. From 2010-2012, he was Secretary General of AOGS. In addition, he has served on many other national and international committees. He was a member of the Advisory Board of the Ocean Acidification International Coordination Centre (OA-ICC). He is a member of the expert group of the High-level panel for a Sustainable Ocean Economy, and a member of the China Council for International Cooperation on Environment and Development (CCICED). He was co-chair of the Programme Committee of the OceanObs’19 Conference and he is currently co-chairing the international program: Surface Ocean and Low Atmosphere Study (SOLAS).