Central European climate variability during the Eocene hothouse

A previously unknown 'hyperthermal-like' warming event, correlating with marine isotopic excursions, has been identified in the Messel Pit Fossil Site record, suggesting that profound global warming events occurred more frequently during the Eocene than previously assumed. This discovery challenges the understanding of climate variability in past warm periods. The study utilized biomarkers from annually resolved maar lake sediments to reconstruct sub-millennial to millennial-scale temperature dynamics over a ~430 thousand-year period (47.7 to 47.2 million years ago). It revealed nonlinear warming of up to 3.5°C during the hyperthermal event, modulated by Earth's orbital cycles, and significant ecological changes in the lake ecosystem. Additionally, the research demonstrated that the Eocene climate transitioned from an unstable state with 5°C fluctuations to a stable state with only 2°C variability, likely driven by orbital configuration. Hydrogen isotopic analysis further indicated a decoupling of the hydrological cycle from regional temperature history and shifts in relative humidity of up to 60%.

Schmitt, C. Central European climate variability during the Eocene hothouse. https://doi.org/10.21248/gups.96764