Strong Coupling Between Carbon Cycle, Climate, and Weathering During the Paleocene-Eocene Thermal Maximum

Abstract

The Paleocene-Eocene Thermal Maximum (PETM; ∼56 Ma)–a geologically rapid carbon-release event similar to anthropogenic carbon emissions–is ideal for investigating weathering responses to rapid carbon release and associated climate change. Here, for the first time, we present high-resolution lacustrine lithium isotope data that reflect basin-scale silicate weathering across the PETM in the Nanyang Basin, eastern China. Our results reveal an ∼100% increase in regional silicate weathering intensity through the PETM relative to the pre-PETM level. Synchronous variations between carbon isotope values and weathering intensity demonstrate a strong coupling between carbon cycle, climate, and chemical weathering on millennial timescales. These findings argue that strong negative weathering feedback and massive removal of CO2 maintained Earth's climate within a habitable range during the PETM.