The overarching motivation for Dr. Rosenthal’s research is to document the history of, and understand mechanisms of climate change. As the ocean plays a key role in climate, a full understanding of the complexity of past climate change requires thorough knowledge of variations in ocean hydrography (e.g., seawater temperature, salinity and heat content) and circulation through time. Throughout his career, he 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.