A wedge strategy for mitigation of urban warming in future climate scenarios
Lei Zhao1,2,3, Xuhui Lee2,3, and Natalie Schultz31Program in Science, Technology and Environmental Policy (STEP), Woodrow Wilson School of Public and International Affairs, Princeton University, Princeton, New Jersey, 08540, USA 2Yale-NUIST Center on Atmospheric Environment, Nanjing University of Information Science and Technology, Nanjing, 210044, China 3School of Forestry and Environmental Studies, Yale University, New Haven, Connecticut, 06511, USA
Received: 23 Nov 2016 – Accepted for review: 09 Jan 2017 – Discussion started: 16 Jan 2017
Abstract. Heat stress is one of the most severe climate threats to the human society in a future warmer world. The situation is further compounded in urban areas by the urban heat island (UHI). Because the majority of world's population is projected to live in cities, there is a pressing need to find effective solutions for the high temperature problem. We use a climate model to investigate the effectiveness of urban heat mitigation strategies: cool roofs, street vegetation, green roofs, and reflective pavement. Our results show that by adopting highly-reflective roofs, almost all the cities in the United States and southern Canada are transformed into white oases at midday, with an average oasis effect of −3.4 K in the summer for the period 2071–2100, which offsets approximately 80 % of the greenhouse gas (GHG) warming projected for the same period under the RCP4.5 scenario. A UHI mitigation wedge consisting of cool roofs, street vegetation and reflective pavement has the potential to eliminate the daytime UHI plus the GHG warming.
Zhao, L., Lee, X., and Schultz, N.: A wedge strategy for mitigation of urban warming in future climate scenarios, Atmos. Chem. Phys. Discuss., doi:10.5194/acp-2016-1046, in review, 2017.