Blue Zones: Identifying Adaptation Opportunities Using Past, Present, and Future Flooding in New York City

Climate change poses escalating risks to urban populations and infrastructure, making adaptation strategies urgent. We overlaid the pre‐urban, natural hydrology of New York City's five boroughs with places that flood today and predictions of future flooding to identify coincident localities (“Blue Zones”) where adaptation is needed. We identified 538 Blue Zones, which collectively cover 21% of the city's land area, affecting approximately 1.2 million people and 11% of city buildings. Over two‐thirds of the flood‐prone area is estimated to be threatened by coastal flooding; 36% from combined coastal and pluvial flooding; and 5% from pluvial flooding only. Analysis of land tenure revealed that two‐thirds of Blue Zone area is managed by government entities. Urban historical ecology provides important insights not only about the past but the future of cities.