Growth of subtropical forests in Miocene Europe: The roles of carbon dioxide and Antarctic ice volume

• Published in: Geology
• Main Authors: Hamon, Noémie, Sepulchre, Pierre, Donnadieu, Yannick, Henrot, Alexandra-Jane, François, Louis, Jaeger, Jean-Jacques, Ramstein, Gilles
• Other Authors: Unité de Modélisation du Climat et des Cycles Biogéochimiques, Université de Liège
• Format: Article in Journal/Newspaper
• Language: English
• Published: Geological Society of America 2012
• Subjects: Miocene; climate; modelling; Physical; chemical; mathematical & earth Sciences; Earth sciences & physical geography; Physique; chimie; mathématiques & sciences de la terre; Sciences de la terre & géographie physique; Antarc*; Antarctic; Antarctica; Ice Sheet
• Online Access: https://orbi.uliege.be/handle/2268/117251; https://doi.org/10.1130/G32990.1

peer reviewed The middle Miocene is a crucial period for the evolution of apes, and it corresponds to their appearance in Europe. The dispersion of apes was made possible by tectonic changes and the expansion of their habitat, (sub-) tropical forest, in Europe. The context in which the middle Miocene climatic optimum occurred still lacks constraints in terms of atmospheric pCO2 and ice-sheet volume and extent. Using a coupled atmosphere-ocean general circulation model (GCM) and dynamic vegetation model, we investigated the sensitivity of Miocene climate and vegetation to pCO2 levels and Antarctic ice-sheet confi gurations. Our results indicate that higher than present pCO2 is necessary to simulate subtropical forest in Western and Central Europe during the middle Miocene, but that a threshold at high pCO2 makes subtropical forest partly collapse. Moreover, removing ice over Antarctica modifi es oceanic circulation and induces warmer and slightly wetter conditions in Europe, which are consistent with the expansion of subtropical forest. These results suggest that a small East Antarctic Ice Sheet (25% of present-day ice volume) together with higher than present pCO2 values are in better agreement with available European middle Miocene data. Comprendre le refroidissement du Cénozoïque