Thermal buffering of forest greening across spatiotemporal scales in China

Abstract Pronounced forest greening is observed in China due to national ecological restoration. However, the biophysical effects of forest greening on local thermal environment in China across different spatiotemporal scales have not yet been assessed. By integrating multiple satellite datasets with land surface model simulations, we show that from 2001 to 2020, approximately 97% of forested areas in China exhibited an overall greening trend of 0.352 m 2 m −2 decade −1 . Forest greening in China exerted a daily cooling effect of 0.146°C per decade across more than 98% of forested areas through biophysical processes, with the magnitude of cooling increasing toward lower latitudes. The competition among changes in shortwave radiation (SW), latent heat (LE), and sensible heat (H) induced by forest greening is the primary biophysical process influencing surface temperature. On an annual scale, the contributions of leaf area index (LAI)‐induced changes in SW, LE, and H to land surface temperature (LST) variations averaged 6.31%, 47.87%, and 43.42%, respectively. LAI changes dominated the annual mean surface temperature change of needle forests through changes in H and in deciduous broadleaf forests through changes in LE. In evergreen broadleaf forests, the dominant biophysical process varied by season, with H contributing more in autumn and winter and LE playing a larger role in spring and summer. These findings highlight the importance of sustainable forest restoration in enhancing thermal buffering capacity under climate change.