Contrasting urban and rural heat stress responses to climate change

During heatwaves, the urban heat stress amplification is particularly pronounced. Heat stress strongly increases with doubled CO₂ concentrations over both urban and rural surfaces. The tropics experience the greatest increase in number of high-heat-stress nights, despite a relatively weak ∼2°C warming.

Given the lack of a distinct annual cycle and high relative humidity, the modest tropical warming leads to exceedance of the present-day record levels during more than half of the year in tropical regions, where adaptive capacity is often low. While the absolute urban and rural heat stress response to 2 × CO₂ is similar, the occurrence of nights with extremely high heat stress increases more in cities than surrounding rural areas.