Abrupt changes and the astronomical theory of climate?

• Main Authors: Rousseau, Denis-Didier, Bagniewski, Witold, Ghil, Michael
• Other Authors: Lamont-Doherty Earth Observatory (LDEO), Columbia University New York, Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Géosciences Montpellier, Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA)-Université de Montpellier (UM)-Institut national des sciences de l'Univers (INSU - CNRS)
• Format: Report
• Language: English
• Published: HAL CCSD 2021
• Subjects: Abrupt climate changes; Astronomical theory; ice sheets; Dansgaard-Oeschger events; Bond cycles; [SDE.MCG]Environmental Sciences/Global Changes
• Online Access: https://hal-insu.archives-ouvertes.fr/insu-03299662; https://hal-insu.archives-ouvertes.fr/insu-03299662/document; https://hal-insu.archives-ouvertes.fr/insu-03299662/file/rousseau_Milankovic_extended-abstract_V4.pdf

The past 3.2 Myr have seen drastic climate changes with the development, waxing and waning of huge continental ice sheets over the Northern Hemisphere. These striking phenomena have been observed in various records from ice cores, as well as marine and terrestrial sediments. These proxy records showed periodicities associated with the three orbital parameters that affect our planet's insolation, namely eccentricity, obliquity and precession. Until recently, these periodicities were considered as the canonical ones for the Quaternary Period and beyond. However, the improvement of the time resolution of available records has allowed one to describe climate changes occurring abruptly and with periodicities that are not related to those of the orbital parameters. In this paper, we show that, in fact, these abrupt climate changes may still be related, albeit indirectly, to the astronomical theory of climate.