How do we know human impact on our oceans is impairing the health of our planet? The ocean plays a major role in regulating Earth’s temperature through exchange of chemicals and microbes with the atmosphere. When waves break, ocean-derived biological species including viruses and bacteria are transferred into the atmosphere. These species can ultimately form clouds, altering precipitation and climate. Highlights will be presented of novel experiments being conducted in a unique ocean-atmosphere simulator developed by the National Science Foundation (NSF) Center for Aerosol Impacts on Chemistry of the Environment (CAICE). This presentation will focus on recent CAICE studies aimed at advancing our understanding of how the oceans influence human and planetary health. New insights will be discussed as well as future studies designed to unravel human versus microbial impacts on the changing Earth’s system. Guest Speaker: Kimberly Prather, Ph.D., Professor, Climate, Atmospheric Science, and Physical Oceanography at UC San Diego.