Interglacials as test bed for climate change and variability in climate models

Paleoclimate data play a crucial role in validating advanced coupled climate models by offering insights into past climate transitions, which can inform our understanding of potential future conditions that may diverge significantly from today's climate. By examining past warm periods, we can assess the performance of climate models during interglacials and potential future warmer climates. This talk will highlight how integrating paleoclimate records with climate model simulations helps bridge knowledge gaps, focusing on the impact of ocean circulation, extreme weather events, and spatio-temporal dynamics in a warming world. Focus will be on interglacial sea surface temperatures, The higher the resolution, the higher is the spatial heterogeneity. Additionally, our Earth system model now incorporates an interactive cryosphere component, enabling us to simulate changes in both Antarctica and the Northern Hemisphere effectively. Theses feedbacks are essential for previous interglacials and the future.

As a second related aspect, current Earth system models are limited in their ability to accurately capture climate variability across different temporal scales, particularly underestimating temperature trends, multidecadal to centennial fluctuations. In this study, we show that high-resolution climate simulations with explicitly resolved sub-mesoscale ocean eddies, reveal increased long-term variability in the tropics, while simultaneously reducing interannual variability. This shift in spectral power, from dominance by interannual to multidecadal timescales, has significant implications for understanding past climate variability, refining future climate projections, and enhancing the detection of anthropogenic climate change.