Urbanization experiences different speeds and forms under diverse development stages across the globe. However, urbanization-induced impacts on long-term surface urban heat island intensity (I_s) trends across global cities and the regulators of such impacts remain understudied Here we estimate interannual trends in daytime I_s (i.e., urban-rural differences in surface temperatures) across 511 major cities for 1985–2020 using annual averages calculated using reconstructed land surface temperature data derived from >250,000 Landsat thermal images. Our study reveals that the global mean I_s growth rate is 0.156 °C/decade. We further examine I_s change associated with per 1% impervious land growth (denoted as β) in each city throughout the research period and during different periods. The global mean β is 0.018 ± 0.025 °C/% (mean ± 1 standard deviation) for the whole period, with greater values in humid than in arid climates; and the β may change during different periods, e.g., it has more than tripled when urban impervious land exceeds 30%, indicating the spatiotemporally divergent impacts of urbanization on I_s trends across global cities. The spatial variations in β across global cities are well correlated with rural vegetation abundance and precipitation but not with urban population. Among these three factors, rural vegetation abundance possesses the greatest standardized regression coefficient of partial least-squares model, signifying the critical role of biome background in regulating β. The finding implies that future urbanization over densely vegetated regions should be more carefully and strategically planned due to the greater urbanization-induced surface warming effect.

全球不同发展阶段的城镇化进程呈现出不同的速度和形式。然而，城市化对全球城市长期地表城市热岛强度 ( I _s ) 趋势的影响以及此类影响的调节因素仍未得到充分研究。在这里，我们估计白天I _s的年际趋势（即地表温度的城乡差异） ) 1985-2020 年 511 个主要城市的年度平均值，使用从 >250,000 张 Landsat 热图像中获得的重建地表温度数据计算得出。我们的研究表明，全球平均_Is增长率为 0.156 °C/十年。我们进一步检查I _s在整个研究期间和不同时期，每个城市每 1% 的不透水土地增长（表示为β ）相关的变化。整个时期的全球平均值β为 0.018 ± 0.025 °C/%（平均值 ± 1 个标准差），潮湿气候下的值大于干旱气候下的值；并且β可能会在不同时期发生变化，例如，当城市不透水土地超过 30% 时，它会增加两倍以上，表明城市化对全球城市I_趋势的时空差异影响。β的空间变化全球城市的人口增长与农村植被丰度和降水量密切相关，但与城市人口无关。在这三个因素中，农村植被丰度具有最大的偏最小二乘模型标准化回归系数，表明生物群落背景对调节β的关键作用。这一发现表明，由于城市化引起的地表变暖效应更大，未来在植被茂密地区的城市化应该更加谨慎和战略性地规划。