Changes in the Earth's coupled ocean-atmosphere system are among the most pressing issues facing science and society. IGPMS students and faculty are at the leading edge of this research using the latest empirical, observational, and modeling approaches to understand the response of the Earth system to global climate change, now and in the past. Examples of research in this area include developing satellite remote sensing tools to understand carbon export, measuring how ocean currents affect the distribution of carbon and other nutrients, reconstructing ocean circulation from paleoclimate records, and using trace gases to understand the biogeochemical cycling of carbon. Modelers use inverse models to understand the exchange of carbon and heat between the ocean and atmosphere, and global ocean and climate models to understand the ocean's role in large-scale climate variability and future climate change.