Advancing Climate System Understanding: Insights from the PalMod Project

The PalMod project, funded by the German Federal Ministry of Education and Research (BMBF), aims at addressing key knowledge gaps in the understanding of the dynamics and variability of the climate system during the last glacial cycle. This period, which is marked by strong and rapid climatic fluctuations, serves as a testbed for complex Earth system models (ESMs). The models tested in this way will be used in climate-change scenarios for the next millennia to enhance future climate-change assessments. PalMod uses three ESMs—AWI-ESM, MPI-ESM, and CESM— that integrate physical and biogeochemical processes and employ advanced parameterizations regarding, for example, ice sheet-ocean interactions.In Phases I and II, the project focused on key epochs of the last glacial cycle including inception, MIS3, and the last deglaciation. The ongoing final Phase III leverages these insights to project the climate over the next millennia. Central to this last project phase is to answer some of the major societally critical questions in association with climate change: What are the potential tipping points and at which global warming may they become relevant? Under what conditions could polar ice sheets collapse catastrophically, and how rapidly could sea levels rise under different future climate scenarios? How will permafrost evolve in a warming world? This presentation reflects on the progress made during the past two phases of the project and presents preliminary answers to the aforementioned pressing questions.