Long-term Effects of Redlining on Climate Risk Exposure (Revised September 2023)
Climate change amplifies environmental hazards, including extreme precipitation and heat events. These hazards are further exacerbated by urban design features like impervious land surfaces and insufficient tree cover. While the enduring socioeconomic impacts of redlining—a policy that systematically denied financial services to specific neighborhoods—are well-studied, its long-term effects on vulnerability to climate risks remain under-explored. Using a boundary design methodology, our study examines 202 U.S. cities and reveals that neighborhoods that were redlined in the 1930s-1940s by the Home Owners' Loan Corporation face disproportionately higher risks of both current and future flooding and extreme heat. These heightened vulnerabilities are at least partly due to diminished environmental capital in the present day—most notably, reduced tree canopy and lower ground surface permeability. Our findings underscore the persistent and far-reaching influence of historical redlining policies in shaping unequal climate risk exposure.