More intense and equal compound heatwaves driven by urbanization

This study analyzes urban compound heatwaves (UCHWs) and associated inequalities across 936 cities worldwide. The findings indicate a sustained increase in UCHWs under global urbanization, alongside a general decline in associated inequalities between 2003 and 2019. This pattern is especially pronounced in the Global South, where the intensification of UCHWs has exceeded that of the Global North, while reductions in related inequalities have been more substantial. Urbanization contributes to the intensification of UCHWs by increasing impervious surfaces and reducing urban greenery, while simultaneously decreasing spatial heterogeneity and, in turn, UCHW inequality. The study underscores the influence of urbanization on both heatwave dynamics and their unequal impacts, with important implications for urban sustainability. As urban populations face growing exposure to severe and uneven heat extremes, the analysis addresses a key gap in existing research by examining how urbanization shapes not only urban heatwaves but also the inequalities associated with them.