Potential benefit of electric vehicles in counteracting future urban warming: A case study of Hong Kong

Abstract

• Warming effects by vehicle heat intensify in winter but shrink in summer in 2050 • Adopting electric vehicles can offset 25.5% of the future warming in winter • Electric vehicles provide limited cooling benefit to Hong Kong in summer • Carsharing system provides negligible cooling benefit at the city scale The global electric vehicle (EV) market is undergoing rapid expansion. EV adoption can reduce vehicle heat (VH) emissions on the road, yet its potential benefit to the urban thermal environment has rarely been investigated. In this study, we examine the cooling benefit of EV adoption and its combination with the carsharing system under future climates using numerical weather simulations. Under the worst scenario, the urban air temperature will increase by 0.90 °C in January and 1.47 °C in July by 2050 in Hong Kong. The warming effect of VH is found to intensify in winter and shrink in summer under future climates. In winter, EV adoption can offset 25.5% (0.23 °C) of the global warming signal at the city scale, and the benefit is most distinct during the evening. However, EV adoption provides less cooling in summer when the global warming signal is more evident. By saving parking spaces and converting them into outdoor green spaces, the carsharing system can provide additional cooling benefits only during the evening rush period in winter. Our results provide insights into the potential benefits of green transportation technology in urban heat mitigation.