Future extreme high-temperature risk in the Beijing-Tianjin-Hebei urban agglomeration of China based on a regional climate model coupled with urban parameterization scheme

Projecting the future extreme high-temperature risk under the background of global warming and urbanization is essential to the collaborative development of Beijing, Tianjin, and Hebei (BTH). In this study, based on the global climate simulation data from the Coupled Model Intercomparison Project Phase 6 (CMIP6) and the fine land-cover data, we use the Weather Research and Forecast (WRF) model coupled with the building effect parameterization (BEP) and building energy model (BEM) at 3-km grid spacing to project the changes in the intensity, frequency, and risk of extreme high temperature over the BTH urban agglomeration. The results show that under the future shared socioeconomic pathway scenario (SSP245), the average extreme high-temperature intensity (EHI) in the BTH will increase by 0.71 degrees C and 2.12 degrees C in the middle and late twenty-first century, respectively, compared with that in the reference period (2005-2014), which are 0.23 celcius and 0.58 celcius more than that only considering global warming, respectively. The average extreme high-temperature frequency (EHF) will increase by 99 h and 200 h, 53 h and 72 h more than that considering only climate change, respectively. The average high-temperature risk in the BTH for 20-year and 50-year return periods will increase by 1.9 times and 2.4 times in the middle twenty-first century, respectively, and expand to 8.0 times and 12.9 times in the late twenty-first century, respectively. Therefore, it is necessary to take adaptation approaches to reduce the future risk of extreme high-temperature events in the BTH.

Automated summary

Based on global climate simulation data and fine land-cover data, this study uses a coupled model with parameterization and energy model to project the changes in extreme high-temperature risk in the Beijing-Tianjin-Hebei region. The results indicate that under future scenarios, there will be significant increases in high-temperature intensity, frequency, and risk. Therefore, adaptation measures are necessary to reduce future high-temperature risks.