Agenda

Speaker: Prof. Yair Rosenthal, Rutgers University

Link Zoom

Abstract:
A ~fivefold decrease in the atmospheric concentration of CO2 took place during the Cenozoic. This has often been viewed within the context of silicate weathering changes, but the specific contributions of other potential drivers remain poorly understood. Recently, it has been alternatively argued that changes in the sea floor spreading rate and hence degassing contributed to the Cenozoic pCO2 decline. However, an insufficient decrease in spreading occurred for this to account for the entirety of the pCO2 change. One previously overlooked factor is the consequent change in the major element composition of seawater, especially the concentration of calcium ([Ca2+sw]), which is typically viewed as responding to processes such as weathering, rather than representing a driver in and of itself. In this talk I’ll examine mechanisms that contributed to the change in Cenozoic pCO2, and question the idea of its long-term balance.

Bio Sketch:
Yair Rosenthal is Distinguished Professor at Rutgers, the State University of New Jersey, Departments of Marine Sciences and Earth and Planetary Sciences. He is a recognized leader in the Integrated Ocean Drilling Program and, because of this contribution to the Earth Sciences, has been nominated Fellow of the American Geophysical Union (AGU). The overarching motivation for his research is to document the history of, and understand mechanisms of climate change. Throughout his career, Yair has endeavored to develop new geochemical proxies that offer quantitative information of past ocean properties and thus the possibility for rigorous paleoceanographic reconstructions in a similar manner to that conducted with modern data.