In the last decade, unprecedented storm events—from Superstorm Sandy to hurricanes Harvey, Irma, and Maria— have sent a clear message to coastal cities across the nation: We must do more to anticipate and manage severe flooding and other climate-related disruptions. Some cities have already begun this work by mapping their vulnerabilities and looking for ways to enhance their resilience. New York, San Francisco, and Boston are among those considering changes in land-use regulation, investments in conservation, and infrastructure modifications aimed at protecting high-value coastal areas and the people who live and work in them. Philanthropic initiatives such as the Rockefeller Foundation’s 100 Resilient Cities have helped in this regard.