This study investigates the urban surface warming trends using satellite land surface temperatures (LST) from 2002 to 2021 for over 2000 city clusters worldwide. The results show that the mean surface warming trend in urban cores is 0.50 ± 0.20 K per decade, which is 29% greater than the trend in rural background areas. Background climate change is the largest contributor to urban warming, but urban expansion significantly impacts warming in China and India. Urban greening, observed in European cities, offsets background warming. The study highlights the need to consider the different warming rates between urban and rural areas in assessments of heat-related health impacts and future projections.

Zihan Liu, Wenfeng Zhan, Benjamin Bechtel, James Voogt, Jiameng Lai, Tirthankar Chakraborty, Zhi-Hua Wang, Manchun Li, Fan Huang, Xuhui Lee