Increasing heatwave with associated population and GDP exposure in North China

Twenty-seven CMIP6 models were grouped into three ensembles based on the simulated performance of heatwaves in North China during present-day (1995-2014), and future changes in the duration and intensity of heatwaves were projected under SSP1-2.6, SSP2-4.5 and SSP5-8.5. The selected three ensembles showed consistent projections: both the duration and intensity of heatwaves would increase significantly, with the greatest under SSP5-8.5. Besides, the heatwave growth in 2081-2100 would double in 2041-2060, except for SSP1-2.6, where heatwaves would be similar in both periods. For the spatial distribution, the duration (intensity) would increase more in southern (western) parts of North China. Combining heatwaves with population and GDP, future heat exposures would concentrate on urban areas and the tertiary industry. For example, the 2041-2060 population exposure would reach 3.2-5.6 times the current level, with contributions from the urban population ranging from 55% to 60%. The GDP exposure would hit tens to hundreds of times the current level, with the tertiary sector replacing the secondary sector as the leading industry in North China, producing the major contribution and facing significant heat-related risks. Overall, there will be significant heat-related impacts under SSP5-8.5, about 1.5-3.0 fold of those under SSP1-2.6 and SSP2-4.5. The urban and tertiary sectors would suffer greater risks relative to the rural and other industries. Our results reinforced the need to minimize global emissions and develop strategic plans to mitigate heat impacts under high-emission scenarios, especially for urban areas and the tertiary industry, requiring great attention to climate adaptation.