TIPMIP: The Tipping Points Modelling Intercomparison Project

Ocean-Cryosphere Exchange in Antarctica: Impacts on Climate and the Earth System Speaker: Torsten Albrecht (PIK) Event: OCEAN ICE annual meeting in Copenhagen Date: Tuesday Sept. 16th, 2025 Disclaimer: Funded by the European Union. Views and opinions expressed are however those of the authors only and do not necessarily reflect those of the European Union or European Research Executive Agency (REA). Neither the European Union nor the granting authority can be held responsible for them. UK Partners are funded by UK Research and Innovation (UKRI) under the UK government’s Horizon Europe funding Guarantee. Update on TIPMIP activities https://tipmip.org The Tipping Points Modelling Intercomparison Project overview See what happens Make it happen It has happened Experiment simulation time forcing Winkelmann et al., TIPMIP framework paper (in review) TIPMIP-ESM Protocol Jones et al., TIPMIP-ESM protocol (submitted.) Experiment simulation time forcing ●Aligned in temperature space ●Protocols for concentrationand emissions-driven models ●9 models already participated, more to come ●setting up TIPMIP database and “How-to” page for data download/submission TIPMIP-Ocean Protocol Experiment simulation time forcing A. CO2+hosing •What is the impact of an AMOC collapse at 2°C warming? Can it be followed by a recovery? • Closely linked to TipMIP-ESM : • Ramp up run with constant CO2 emissions yielding a warming of ~ 2°C/century with increasing freshwater from 0 to 0.3 Sv or 0.1 Sv in 100 years • Zero emission run starting at GWL=2°C, branching off with freshwater release kept at 0.3 Sv or 0.1 Sv • Ramp down simulation with CO2 emissions that are the negative of those used in, branching off with freshwater release kept at 0.3 Sv or 0.1 Sv after 50 years. • Stop hosing and run until stabilisation at 0°C warming and 0 Sv hosing (checking recovery after a collapse (if any) B. Greenland melting in recent past and future •How did/will the AMOC respond to realistic and projected sources of Greenland freshwater? •Insert in the model Greenland Ice Sheet Melting considering historical Greenland Ice Melting amounts (from Mankoff et al. 2025) + 80 years projections of melting considering Ice-Sheets models ensemble with different warming scenarios 2°C or 4°C C. NAHosMIP •Will AMOC recover after significant freshwater perturbation? •Starting from piCtrl, NaHosMIP (Jackson et al., 2013) uniform NA hosing of 0.3 Sv or 0.1 Sv D. 8.2 kyr event •What do CMIP models say about AMOC response and impacts of Laurentide-type freshwater release? •Mimic the 8.2kyr event: Ramp-up to 0.6Sv/century leads to a total amount of 15 Sv, as suggested in Lochte et al. (2019) (corresponding to the same amount of water as 50 years of NAHosMIP) Thanks to Didier Swingedouw, Laura Jackson, Wilbert Weijer, Aixue Hu and Nicole Laureanti! https://tipmip.org/ocean-domain TIPMIP-Ice -Currency pilot experiments and ESM choice and preprocessing - Protocol draft planned for Dec 2025 - Experiment submission ideally July 2026 - Envisaged manuscript submission ideally Dec 2026 -Climate ramp-up (~200yr) - Climate stabilization / commitment (at 2°C and 4°C for ≥1000yr) -Climate reversibility (to 1.5°C for ≥1000yr) -Control at pre-industrial climate based on TIPMIP-ESM experiments TIPMIP-Ice -Currency pilot experiments and ESM choice and preprocessing - Protocol draft planned for Dec 2025 - Experiment submission Jul 2026 - Envisaged manuscript submission Dec 2026 TIPMIP dates - Global Tipping Points Report 2025: publication & presentation at COP30 - WCRP/IPCC meeting on Tipping Points: 26-28 Nov 2025 in Paris - Domain Leads meeting: 2-4 Dec 2025 in Potsdam - TIPMIP General Assembly: 4-6 March 2026 in Tokyo (ahead of CMIP Community Workshop) https://tipmip.org