Modeling the Urban Climate at the Human Scale in Hot/Dry Regions Dr. Benjamin L. Ruddell Assistant Professor, Department of Engineering, Arizona State University firstname.lastname@example.org Although most of the human impacts of global and local climate change will be felt in cities, and despite the fact that the connections between the sustainability of human health and economics, water, and energy are arguably the strongest in cities, our descriptive and modeling capabilities for the Earth System remain relatively weak at the critical "human scale" at or below 100 meters at which the urban environment is built and managed and at which people live their lives. A project funded by the Earth Systems Modeling (EaSM, of the NSF's SEES Initiative) program is demonstrating the computational feasibility and empirically validated accuracy of a coupled tRIBS/WRF model for regional climate model downscaling and microclimate modeling at 100m urban neighborhood scales. Unique urban microclimate observational data is utilized for model development and validation. The resulting coupled model will have the potential to transform urban microclimate modeling and urban climate change adaptation decision making through the analysis and distribution of neighborhood (and smaller scale) data. Working results of modeling and observational efforts are presented for applications in the Phoenix metropolitan area. This type of model will provide a tool for designing urban neighborhoods that are resilient in scenarios of climate and economic change, optimizing tradeoffs between water, energy, environmental, and social outcomes.