The Antarctic response to a 1% annual increase in atmospheric CO2

Grant Agreement Number: 101137601 The Antarctic response to a 1% Annual Increase in Atmospheric CO₂ Javier Blasco1, Britta Grusdt1, Marisa Montoya2,3, Jorge Alvarez-Solas2,3, Alexander Robinson1 1Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Potsdam, Germany 2Departamento de Física de la Tierra y Astrofísica, Facultad de Ciencias Físicas, Universidad Complutense de Madrid, Madrid, Spain 3Instituto de Geociencias, Consejo Superior de Investigaciones Científicas, Universidad Complutense de Madrid, Madrid, Spain T6.1 Baseline experiments and long-term commitment The Antarctic Ice Sheet evolution 2ClimTip | Quantifying Climate Tipping Points and Their Impacts GRACE satellite. Mouginot & Schleuch (2018) The Antarctic Ice Sheet as tipping element 3ClimTip | Quantifying Climate Tipping Points and Their Impacts Pattyn, (2018). BedMachine Antarctica (2019) The Antarctic Ice Sheet as tipping element 4ClimTip | Quantifying Climate Tipping Points and Their Impacts We know that the tipping point of WAIS lies between 1-3 K of oceanic temperature increase. Rohling et al., (2019) Garbe et al., (2020) ClimTip & TipMIP experimental design 5ClimTip | Quantifying Climate Tipping Points and Their Impacts Effect of climate variability 6ClimTip | Quantifying Climate Tipping Points and Their Impacts “We conclude that internal climate variability alone can be responsible for significant uncertainty in projections of sea-level rise.” (Robel et al., 2019) “Internal climate variability affects the Antarctic contribution to sea-level change until 2100 by 45 % to 93 % depending on the CMIP6 model” (Caillet et al., 2025) 1990-2019 period 7ClimTip | Quantifying Climate Tipping Points and Their Impacts RACMO2.3p2 van Wessem et al., (2023) ORAS5 Reanalysis Copernicus Climate Change Service, Climate Data Store, (2021) Control runs 8ClimTip | Quantifying Climate Tipping Points and Their Impacts (Seroussi et al., 2024) CV Mean 1990-2019 Experimental setup 9ClimTip | Quantifying Climate Tipping Points and Their Impacts 16ClimTip | Quantifying Climate Tipping Points and Their Impacts Year 4000Year 5000 Oceanic sensitivity Conclusions & Future work 17ClimTip | Quantifying Climate Tipping Points and Their Impacts -Initialization scheme affects the tipping point. WAIS collapse - mean climatology: 1.5 K - climate variability: 1.3 K -Delayed response of 1000 years between climate variability and mean climatology. -Precipitation can delay also collapse by centuries. Next steps: -Ensembles to investigate tipping point behaviour for a range of uncertainties. -Forcing with ESM outputs. What polar amplification do ESM simulate? And oceanic temperatures? -Greenland simulations. Grant Agreement Number: 101137601 Thank you for your attention! ☺ javier[email protected] climate-tipping-points.eu Funded by the European Union. Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or the European Climate, Infrastructure and Environment Executive Agency (CINEA). Neither the European Union nor the granting authority can be held responsible for them. © ClimTip Consortium, 2024 Experimental setup 19ClimTip | Quantifying Climate Tipping Points and Their Impacts RACMO2.3p2 van Wessem et al., (2023) ORAS5 Reanalysis Copernicus Climate Change Service, Climate Data Store, (2021) 2 spinups - 1 with climate variability - 1 without climate variability Spinup comparison 20ClimTip | Quantifying Climate Tipping Points and Their Impacts Nudging method 21ClimTip | Quantifying Climate Tipping Points and Their Impacts Corr Corr 22ClimTip | Quantifying Climate Tipping Points and Their Impacts 23ClimTip | Quantifying Climate Tipping Points and Their Impacts Interactive oceanic extrapolation 24ClimTip | Quantifying Climate Tipping Points and Their Impacts 25ClimTip | Quantifying Climate Tipping Points and Their Impacts