Due to its rapid growth, industrialization, and climate characteristics, the Arizona-Sonora region along the U.S.-Mexico border is recognized as a highly vulnerable region in terms of socioeconomic and climate characteristics. Ensuring future water supply is the region’s high­est priority challenge. Climate change projections for reduced precipitation and severe drought. From 2008 to 2011, a binational team of multi-disciplinary researchers led by the University of Arizona and El Colegio de Sonora worked closely with decision-makers, water managers, and disaster relief planners (i.e., stakehold­ers) to conduct urban water vulnerability assessments of the four urban climate change “hotspots” in the Arizona-Sonora region. These assessments focus on the nexus of climate and water variables, with a 5 to 20 year horizon. Project outputs to date include: 1) four linked urban water vulnerability studies (Tucson, AZ; Nogales, AZ., and Nogales, Sonora; Hermosillo and Puerto Peñasco, Sonora) that identify major regional climate-related vulnerabilities and institutional capacity in the water sector; 2) a Binational Climate Summary for Arizona-
Sonora region, in English and Spanish;  3) a series of five stakeholder-scientist workshops; and 4) a new Working Paper series on water, vulnerability, and climate in U.S.-Mexico border region.