Socioeconomic disparities in cooling and warming efficiencies of urban vegetation and impervious surfaces

Abstract

Understanding the temperature regulation effects of urban vegetation and impervious surfaces, as well as how the effects interact with socioeconomic determinants of vulnerability to drive heat risk, is of critical importance for designing effective and equitable heat mitigation strategies. However, existing studies rarely compare temperature regulation efficiencies of diverse urban land cover types, nor do they examine whether distributions of urban vegetation and impervious surfaces could help reduce heat-related inequity by offering more cooling and less warming effects to marginalized communities. By employing satellite and socioeconomic data, this study quantified the cooling efficiencies of urban vegetation and warming efficiencies of impervious surfaces in 44 US cities, and then examined how these efficiencies change across neighborhoods of varying deprivation. We find that urban vegetation, especially trees, has strong cooling effects across different urban contexts, and the cooling efficiencies of urban trees and shrubs/grass are higher in neighborhoods of greater area deprivation. Conversely, buildings and roads produce the largest warming effects, and their warming efficiencies are either greater or at similar levels of magnitude in advantaged neighborhoods, when comparing with deprived neighborhoods. These findings suggest that strategically deploying green and built infrastructure could mitigate heat-related inequity in addition to improving health overall.