Urban Adaptation Strategies Alleviate the Exposure of Future Population to Extreme Heat in China

To cope with the future global extreme high temperatures, three adaptation strategies of green roofs, cool walls, and cool streets are constructed by applying rooftop vegetation planting and building materials of high reflectivity in cities. Hence, there is an urgent need to test these adaptation strategies. This study quantifies the performance of adaptation strategies for mitigating extreme heat in China under the future urbanization and climate conditions using a numerical model. Results are validated using observation data from 839 national meteorological stations in China. Simulation results show that implementing all three adaptation measures will decrease the heat exposure rate by 9.4% by enhancing ground reflection and lowering urban temperature. The contribution of enhancing the albedo of the building walls to reducing exposure is 1.5 times that of using roof planting. These adaptation strategies can reduce urban heat storage, but they may exacerbate urban water vapor accumulation. Most risks are concentrated on the southeast side of the Heihe‐Tengchong Line. The urban geographical locations and population will influence the cooling effect of adaptation strategies. The cool walls have greater cooling effects in southern cities, whereas green roofs are more effective in northern regions. Applying cool walls strategy in densely populated areas of urban buildings can achieve the best cooling effects. When deploying adaptation strategies, not only the cooling capacity but also the climate and development conditions of different cities are necessary to be considered.