Abstract
Urban populations are increasingly exposed to severe and disproportionate heatwaves. While existing studies address urban heatwaves and intra-urban disparities, there remain gaps in understanding of the impact of urbanization on heatwaves and the associated inequalities. In this study, we analyzed urban compound heatwave (UCHW) and associated inequality across 936 global cities. Our findings reveal a sustained increase in UCHW under global urbanization, accompanied by a general decline in associated inequalities from 2003 to 2019. This trend is particularly pronounced in the Global South, where the intensification of UCHWs has outpaced that in the Global North, accompanied by a more significant reduction in related inequalities. Urbanization intensifies UCHWs by increasing impervious surfaces and reducing urban greenery, while concurrently decreasing their spatial heterogeneity and thus lowering UCHW inequality. Our study highlights the impact of the urbanization on UCHWs and associated inequalities, which is crucial for sustainability of cities.
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Data availability
The 2020 Global Urban Boundary (GUB) data are available at https://pan.baidu.com/s/1iBKqLMyEqGnJAtDCLlLPCg?pwd=9s36. The country income group data were obtained from the World Bank’s official website (https://data.worldbank.org/). The daily near-surface air temperature data are available at https://gee-community-catalog.org/projects/airtemp/. Land surface temperature data are available at https://gee-community-catalog.org/projects/daily_lst/. The weather stations through the Global Historical Climatology Network Daily (GHCN-Daily) are available at https://www.ncei.noaa.gov/products/land-based-station. The weather stations through the China Meteorological Data Service Center are available at https://data.cma.cn/. The population data are available at https://developers.google.com/earth-engine/datasets/catalog/WorldPop_GP_100m_pop. The global artificial impervious areas (GAIA) data are available at https://pan.baidu.com/s/1dt8SILPrLCJZBr1NlskrOA?pwd=7tgm. The NDVI data are available at https://developers.google.com/earth-engine/datasets/catalog/MODIS_061_MOD13A1.
Code availability
The Data analysis used Python software, which are publicly available via https://conda-forge.org. The code used to data analysis is available from the corresponding author upon reasonable request.
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Acknowledgements
This work was supported by the National Natural Science Foundation of China (U23A2018, 42171316, 72171128) and in part by Beijing Laboratory of Water Resources Security.
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Y.C. and S.G. designed the study. S.G. analyzed the data and wrote the paper. D.C., B.H., K.L., and P.H. improved the study. All authors contributed to the interpretation of the results.
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Gao, S., Chen, Y., Chen, D. et al. More intense and equal compound heatwaves driven by urbanization. npj Urban Sustain (2026). https://doi.org/10.1038/s42949-026-00363-8
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DOI: https://doi.org/10.1038/s42949-026-00363-8
