Hierarchy of abrupt transitions in the past climate

Denis-Didier Rousseau (1) , Witold Bagniewski , Valerio Lucarini

1 Géosciences Montpellier

The Earth’s climate has experienced numerous critical transitions during its history. Such transitions are evidenced in high-resolution records covering different timescales. This suggests the possibility of identifying, ranking past critical transitions, which yields a more complex perspective on climatic history. Such a context allows defining dynamical climate landscapes with multi-scale features. To illustrate such a richer structure, we have analyzed 2 key high-resolution datasets: the CENOGRID marine compilation (past 66 Myr), and North Atlantic U1308 record (past 3.3 Myr). Our aim was to examine objectively the observed visual evidence of abrupt transitions and to identify among them, the key thresholds indicating regime changes that differentiate among major clusters of variability. This identification is discussed after comparison with major climate factors. A hierarchy in the observed thresholds is proposed through a domino-like succession of abrupt transitions, corresponding to as many bifurcations that shaped the Earth’s climate system over the past 66 Ma.

Domaines: Milieux et Changements globaux; Océan, Atmosphère

Denis-Didier Rousseau, Witold Bagniewski, Valerio Lucarini. Hierarchy of abrupt transitions in the past climate. 2022. ⟨hal-03713538v1⟩