Assessing Volcanic Controls on Miocene Climate Change

The Miocene period saw substantially warmer Earth surface temperatures than today, particularly during a of global warming called the Mid Climatic Optimum (MMCO; ∼17–15 Ma). However, long-term drivers climate remain poorly understood. By using new continuous climate-biogeochemical model (SCION), we can investigate interaction between volcanism, and biogeochemical cycles through Miocene. We identify high tectonic CO2 degassing rates further emissions associated with emplacement Columbia River Basalt Group as primary driver background warmth MMCO respectively. also find that enhanced weathering basaltic terrane input explosive volcanic ash to oceans are not sufficient drive immediate cooling following suggest another mechanism, perhaps change in ocean chemistry due massive evaporite deposition, was responsible.