Satellite observations show widespread increasing trends of leaf area index (LAI), known as the Earth greening. However, the biophysical impacts of this greening on land surface temperature (LST) remain unclear. Here, we quantify the biophysical impacts of Earth greening on LST from 2000 to 2014 and disentangle the contributions of different factors using a physically based attribution model. We find that 93% of the global vegetated area shows negative sensitivity of LST to LAI increase at the annual scale, especially for semiarid woody vegetation. Further considering the LAI trends (P ≤ 0.1), 30% of the global vegetated area is cooled by these trends and 5% is warmed. Aerodynamic resistance is the dominant factor in controlling Earth greening’s biophysical impacts: The increase in LAI produces a decrease in aerodynamic resistance, thereby favoring increased turbulent heat transfer between the land and the atmosphere, especially latent heat flux.

卫星观测显示叶面积指数（LAI）普遍呈上升趋势，被称为地球绿化。然而，这种绿化对地表温度（LST）的生物物理影响仍不清楚。在这里，我们量化了 2000 年至 2014 年地球绿化对 LST 的生物物理影响，并使用基于物理的归因模型解开了不同因素的贡献。我们发现，全球 93% 的植被面积显示出 LST 对 LAI 在年度尺度上增加的负敏感性，特别是对于半干旱木本植被。进一步考虑 LAI 趋势 ( P≤ 0.1)，全球 30% 的植被面积因这些趋势而变冷，而 5% 则变暖。空气动力阻力是控制地球绿化生物物理影响的主要因素：LAI 的增加会降低空气动力阻力，从而有利于增加陆地和大气之间的湍流热传递，尤其是潜热通量。