Enhanced clay formation key in sustaining the Middle Eocene Climatic Optimum

Alexander J. Krause, Appy Sluijs, Robin van der Ploeg, Timothy M. Lenton & Philip A. E. Pogge von Strandmann Abstract The Middle Eocene Climatic Optimum (around 40 million years ago) was a roughly 400,000-year-long global warming phase associated with an increase in atmospheric CO2 concentrations and deep-ocean acidification that interrupted the Eocene’s long-term cooling trend. The unusually long duration, compared with early Eocene global warming phases, is puzzling as temperature-dependent silicate weathering should have provided a negative feedback, drawing down CO2 over this timescale. Here we investigate silicate weathering during this ...