Estuaries are highly productive ecosystems at the terrestrial-aquatic interface. They perform essential ecosystem services while also providing critical habitat for many aquatic species, particularly larval and juvenile fishes. Many estuaries are also heavily developed and densely populated. The fast-growing human population in coastal areas is expected to put additional strain on this critical nexus of water, food, and energy production. Against this backdrop, climate change in the Anthropocene increases stress on these already-taxed ecosystems. Many estuaries are threatened by new hydrologic extremes of both flood and drought, rising sea levels and saltwater intrusion, rising temperatures, invasive species, acidification, eutrophication, harmful algal blooms, and other calamities that threaten the health of human, fish, birds, and other organisms. To find sustainable solutions that address these challenges, scientists must work closely together with resource managers, politicians, and citizen stakeholders to develop solutions that address the many competing needs of these complex environments. While the need for science-based solutions is great, many gaps exist in our understanding of how to best predict, model, and monitor for how a warming climate will change estuarine ecosystems. Small modifications, such as the arrival of an invasive species, can often create complex, non-linear impacts across the entire ecosystem that are inherently difficult to predict. Many existing models were developed to predict one or a few variables, like flow and salinity, and are therefore of limited use for the type of broad-scale synthesis efforts that are necessary to both understand and manage ecosystems as complex as estuaries. Because of this complexity, dedicated long-term monitoring efforts are required to ground-truth these models, but even in the best-studied estuaries their predictions are often beset with considerable uncertainty. This highlights the need not just for increased monitoring and better models, but increased coordination not just within specific systems but across nations in a coordinated effort to build the vital connections needed to share knowledge and best practices to meet this unprecedented global challenge. We have organized this session to bring together a diverse group of thought leaders from different, globally-significant estuaries to share cutting-edge scientific developments on how climate change will continue to affect the physical, chemical, and biological condition of estuarine ecosystems, as well as how these impacts can best be managed and mitigated. In doing so, we will showcase the exciting work being done in this critical area of scientific research and management as well as foster new collaborations.