Research in the Cohen Lab focuses on climate change and its impact on life in the ocean. We are particularly interested in calcification, a process that produces the tiniest seashells, and coral reef ecosystems so big they can be seen from space. Together with organic matter production in the surface oceans, marine calcification exerts significant control on ocean-atmosphere CO2 exchange and is therefore of global biogeochemical significance and critical to survival of myriad kinds of marine organisms. Calcified structures also contain records of past climate, providing a unique and valuable window on oceanographic changes beyond the past 100 years. Our lab utilizes laboratory-based and field experiments and observations to gain insight into the fundamental processes of calcification, to identify the primary biological, physical and biogeochemical drivers of calcification from organism- to ecosystem-scales, and to develop new climate proxies that allow us to build records of ocean climate change spanning the past millenium.