The interplay of timescales in shaping Earth’s climatic history

Pierre Maffre (CEREGE)

Les séminaires du LSCE.


Date de début 22/02/2024 11:00
Date de fin 22/02/2024
Lieu LSCE, Bât 714, pièce 1129 91191 Gif-sur-Yvette


Transient climate evolution sounds familiar for anyone who thinks about anthropogenic global warming. For Earth’s geological history, it is more common to think in terms of steady states (Warmhouse versus Icehouse, for instance). This tendency is perhaps more frequent among modelers, for it is easier to model a steady state.

I want here to make the case that the evolution of climate during Earth’s geological history is likely not an affair of steady states. Long-term climate is in interaction with interlocked global geochemical cycles (carbon, oxygen, sulfur…) whose processes and characteristic timescales range from seasons to tenths of million years. Earth is rather in a permanent transient evolution between everchanging unbalanced forces.

I will present three examples where a combination of different timescales may have shaped Earth’s climate:

  1. the consequences of Pliocene “permanent El Niño” on the silicate weathering carbon sink,
  2. the roles of orbital cycles in Cretaceous anoxic events and climate, and
  3. the effect of increased sulfide oxidation by mountain uplift on global geochemical cycles and climate.

Informations supplémentaires

Laboratoire des Sciences du Climat et de l’Environnement (LSCE-IPSL)
Bât 714, pièce 1129
91191 Gif-sur-Yvette