Anthropogenic carbon release rate unprecedented throughout the Cenozoic

English Abstract:

Carbon release rates from anthropogenic sources have reached a record high of about 10 Pg C/y in 2013. Due to uncertainties in climate system feedbacks, the impact of the rapid carbon release on ocean biogeochemistry and future climate change is difficult predict. Geological analogues from past climate episodes are therefore urgently sought after to guide future climate change assessment. Based on data and models of various past eras and climate episodes, this presentation will provide a paleo-perspective on the magnitude and rate of anthropogenic CO2 emissions, including effects on seawater chemistry, carbonate mineral dissolution, and ocean biogeochemical cycles. Given currently available records, we demonstrate that the present anthropogenic carbon release rate is unprecedented throughout the Cenozoic (past 66 million years). Our results have important implications for our ability to use past analogues to predict future changes, including constraints on climate sensitivity, ocean acidification, and impacts on marine and terrestrial ecosystems.