Join Hokkaido University’s Arctic Research Center and the International Arctic Research Center for the December 2024 Joint Seminar on Ocean Sciences. This webinar features Hiroshi Yoshida with the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) and IARC Deputy Director Claudine Hauri discussing Arctic sea ice decline and changes in shipping in the Northern Sea Route and Bering Strait regions.

Abstracts

Hiroshi Yoshida: How much CO2 should be removed? ~ Design of an electrochemistry-based marine CDR system~ Climate change is advancing rapidly, despite human efforts to reduce GHG emissions. Achieving the global carbon neutrality target for 2050 through emission reductions alone is difficult because emissions cannot be reduced to zero. Carbon dioxide removal (CDR) is a method to remove the remaining GHG emissions. At present, CDR is mainly conducted by nature-based removal (NBR), but from the perspective of durability and total recovery, it is desirable to use technology-based removal (TBR) in combination. In TBR, Direct Air Capture (DAC) is already in operation, but it can also be recovered from the ocean. The carbon density of the ocean is more than 100 times higher than that of the atmosphere, making it more efficient. We are therefore considering the implementation of marine CDR using electrochemistry, and are presenting the system design and basic experiments.

Claudine Hauri: Unveiling Compound Stressors: New Indices and Insights into Gulf of Alaska Ecosystem Vulnerabilities Our ocean biogeochemical model revealed quadruple compound extreme events on the Gulf of Alaska seafloor, driven by ocean acidification, heat, and low oxygen levels during the 2019 marine heatwave—indicating that marine heatwaves alone were not the sole ecosystem stressors. We defined the Northern Gulf of Alaska Climate Oscillation Index and the Gulf of Alaska Downwelling Index, using satellite-observed sea surface height, to analyze how shifting ocean conditions contributed to these events. Our findings emphasize the importance of these newly defined indices in understanding compound stressors and improving predictions of future ecosystem vulnerabilities.