Cities Closed in a Cage of Heat Waves--Shanghai, Hangzhou, Dubai, and Doha--Mid-21st Century

Cities Closed in a Cage of Heat Waves--Shanghai, Hangzhou, Dubai, and Doha--Mid-21st Century

China's North China Plain and East Coast are becoming one of the hottest and most humid regions in the world during the summer. Future climate change is expected to increase the number of days when wet-bulb temperatures approach the tolerance limit of the human body, and dangerous thermal environments may become the norm. When the wet-bulb temperature exceeds 35°C, the body's thermoregulation by sweating will cease to function, and within a few hours, fatal heat stress may occur. In megacities such as Shanghai and Hangzhou, the combination of high population density and the heat island effect further amplifies the heat risk. In these cities, which are economic and logistics hubs, outdoor work and transportation operations will be restricted during heat waves, and lost productivity and strained medical facilities will become real problems.

On the other hand, Dubai and Doha in the Middle East have already introduced air conditioning in public spaces to beat the extreme summer heat. Pedestrian walkways and outdoor commercial facilities are air-conditioned, and air-conditioned bus stops and sidewalks have been installed. Qatar is even more advanced, with stadiums, markets, and even major sidewalks being air-conditioned to allow for outdoor events and sporting competitions. However, such outdoor cooling entails huge electricity consumption and greenhouse gas emissions, and has the paradoxical problem of exacerbating climate change in the long run. In addition, the social risk of widening the gap between those who can benefit from cooling and those who cannot cannot cannot be ignored.