Urban populations face heightened extreme heat risks attributed to urban heat islands and high population densities. Although previous studies have examined global urban population exposure to heatwaves, the influence of urbanization-induced warming is still not quantified. Here, leveraging satellite-derived near-surface air temperature data, we assess the impacts of urbanization-induced warming on heat exposure in 1028 cities worldwide. Additionally, we investigate its role in shaping disparities in heat exposure between global North and South cities. Our findings reveal that urbanization-amplified compound heatwaves exacerbate heat exposure risk in more than 90% of cities, and that this amplification is stronger in high urbanization areas. Moreover, our analysis highlights the potential for overestimating disparities between global North and South cities if urbanization-induced warming is overlooked. The inequality of higher heat exposure in the global South cities than in the global North cities will be narrowed in real scenarios due to more intense urbanization-induced warming in the global North cities. We emphasize the pivotal role of urbanization-induced heatwave intensification in heat exposure assessments and call for its inclusion in future population vulnerability evaluations to extreme heat.

由于城市热岛和高人口密度，城市人口面临着加剧的极端高温风险。尽管之前的研究已经调查了全球城市人口遭受热浪的影响，但城市化引起的变暖的影响仍然没有量化。在这里，我们利用卫星获得的近地表气温数据，评估了城市化引起的变暖对全球 1028 个城市热暴露的影响。此外，我们还调查了它在影响全球南北城市之间热暴露差异方面的作用。我们的研究结果表明，城市化放大的复合热浪加剧了超过 90% 的城市的热暴露风险，并且这种放大在高度城市化地区更为强烈。此外，我们的分析强调，如果忽视城市化引起的变暖，全球南北城市之间的差异可能会被高估。由于全球北方城市的城市化导致的变暖更加严重，全球南方城市与北方城市的高温暴露不平等在实际情况下将会缩小。我们强调城市化引起的热浪加剧在热暴露评估中的关键作用，并呼吁将其纳入未来人口对极端高温的脆弱性评估中​​。