The provision and interpretation of regional-to-local scale weather predictions and climate projections are critical for urban planning, infrastructure development, the delivery of impacts and adaptation strategies, as well as a host of related coupled-modeling, forecasting and assessment efforts. This research theme encompasses more than just Earth system responses (i.e. coupled land, ocean, and atmosphere processes), but also the linked socio-economic and health-related implications of climate change. Accurately modeling the regional response to climate change, and then exploring city-to-street scale (or ocean-to-reef scale) simulations will be central to many of the cross-cutting activities in the CLI, including impact assessments, livability, and ecosystem and human health.