Authors: V. Kelly Turner*, University of California Los Angeles, Ariane Middel, Arizona State University, Florian Schneider, Arizona State University, Zhang Yujia, Arizona State University, Matthew Stiller, Kent State University
Topics: Urban and Regional Planning, Coupled Human and Natural Systems, Hazards and Vulnerability
Keywords: urban climate, design, field methods, environmental planning, urban heat island
Session Type: Paper
Presentation File: No File Uploaded
Cool roofs, pavement, and walls have gained attention as a means to mitigate urban heat island in cities. The use of heat reflective coatings on building surfaces is based on nearly 30 years of research attributing light colored, high albedo surfaces to reductions in surface temperature. Yet, the performance of “cool” surface interventions in practice is not well understood. This talk examines how the City of Los Angles is experimenting with solar reflective coatings through a Cool Pavement pilot program and discusses the challenges of attempting adaptive management practices given the reality of municipal politics. We present, the first field measurements of temperature of cool pavement including measurements of mean radiant temperature (MRT) an indicator of pedestrian thermal comfort and find that heat reflective coatings cool surface temperatures as predicted, but also increase human heat load. Next we discuss how conflicts between science, media, and political framings caused backlash and, in some instances, scaling back of heat mitigation efforts. We find that disambiguating the effects of cool pavement on surface temperature and human thermal comfort made public tradeoffs between urban heat island mitigation and reducing human exposure to extreme heat, and forcing a conversation about how to resolve a normative tension between two policy goals. We conclude that heat reflective coatings are not a policy panacea and discuss lessons learned for urban adaptive management.