Quantifying the Cooling Effect of Urban Greening Driven by Ecological Restoration Projects in China
Dong Xu, Tingting Bai, Lin Yang, Yuyu Zhou, Бин Чэн, Hai Xu, Yongze Song, Yuan Yuan, Yuanzheng Cui, Lin Meng, Ziqian Xia, Min Chen, Zhenci Xu, Peng Zhao, Guihua Dong, Lei Zhang, Jiacheng Zhao, Wanben Wu, Wei Wang, Liu Zhao, Jie Cheng, Philippe Ciais
Abstract
Urban greening (UG) affects local climate by altering surface energy balance, while long-term UG cooling potential, patterns, and contribution to curbing urban warming remain unclear. Here, we designed an novel statistical model to evaluate the cooling potential of UG (CPUG) and created the first CPUG map for China. By exploring the trends in observed and simulated urban surface temperatures (UST), we quantified the CPUG of 0.20 K over the past two decades, which slowed down the warming trend by 14.17% in Chinese cities. We found that the CPUG varied significantly between the urban core and sprawl areas. Specifically, the CPUG in the urban core was approximately 1.01 K, and it contributed to curbing urban warming by 56.08%, which was more than 7.2 times higher than in the sprawl areas, where the CPUG was only 0.14 K and contributed to curbing urban warming by 9.93%. We further revealed that urbanization and major ecological restoration projects are the key factors influencing CPUG, emphasizing the need for anthropogenic vegetation management to curb urban warming. The proposed model in this study provides a powerful tool for quantitatively assessing the impact of long-term UG trends on urban warming. The results of the study are an important reference for building climate-adaptive cities.