21 MAY 2026 (THU) 15:00-16:30
- 14 hours ago
- 2 min read
Departmental Research Seminars Series
Global-scale responses of the Blue Planet to climate and environmental changes: Implications for Earth’s greenhouse gas budgets and the climate system
Date: 21 MAY 2026 (Thursday)
Time: 15:00-16:30 (HKT)
Venue: CLL, Department of Geography, 10/F, The Jockey Club Tower, Centennial Campus, HKU
Meeting ID: 953 9484 8064
Password: 878859
Registration link: TBC
Abstract:
The need to improve the representation of the variability and trends in the transport of carbon (and nutrients) through the land-to-ocean aquatic continuum (LOAC) has been identified as a major knowledge gap in the 6th assessment report of the IPCC1. This incomplete knowledge limits our ability to quantitatively constrain the global budgets of anthropogenic greenhouse gases (GHG: CO2, CH4, N2O) and, ultimately, climate projections. We here briefly review the role of the LOAC in the Earth’s GHG budgets, not only for the present-day fluxes, but also for their anthropogenic perturbations, which result from complex interactions between global change factors (climate and atmospheric composition change) and direct human alterations (e.g., land-use change, hydraulic management). We highlight some major progress recently achieved through combination of data-science, Earth observations and machine-learning, as well as the emerging role of Earth system modeling in the field of LOAC research. Using CO2 as a blueprint, we advocate for a new view of the global carbon cycle that explicitly accounts for LOAC processes, from canopy to open ocean2. The need for community-based ensemble assessments relying on multi-methodological approaches to constrain uncertainties is also stressed, and major remaining knowledge gaps in LOAC science are identified.
Professor Pierre Regnier
Chair Professor, Department of Geoscience, Université Libre de Bruxelles (ULB)
Pierre Regnier obtained his education from Yale University (CT, USA) and the Université Libre de Bruxelles (ULB). He is now Chair Professor at ULB, where he founded the Research Group Biogeochemistry and Modelling of the Earth System (BGEOSYS). In 2023, he was awarded the Hess Distinguished Visiting Professorship from Princeton University, NJ, USA. His research group focuses on the biogeochemistry of carbon and nutrients, global greenhouse gas cycling and climate feedbacks in inland waters, estuaries and the global coastal ocean, modelling of land-ocean interactions and their integration in Earth system models. He has published over 160 papers and book chapters including 13 in Nature journals, of which 8 as first or last author. Pierre Regnier is member of the scientific implementation committee of the Global Carbon Project (GCP), for which he leads the land ocean aquatic continuum component. He is also part of the IOC Expert Working Group on Integrated Ocean Carbon Research for the Intergovernmental Oceanographic Commission (IOC) of the UNESCO and currently serves as European Research Council (ERC) panel committee member. He was also Department Chair in the past, serving two full terms and is now Rector’s counselor for European Research at ULB.
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