Hydrological feedback from projected Earth greening in the 21st century

Jie Wu , Dashan Wang , Laurent Z.X. Li (1) , Zhenzhong Zeng

1 LMD - Laboratoire de Météorologie Dynamique (UMR 8539)

Earth satellites have observed continuous increasing vegetation growth during the past four decades, a phenomenon called Earth greening. Nearly all Earth System Models (ESMs) participating in Coupled Model Intercomparison Project (CMIP) for Intergovernmental Panel on Climate Change (IPCC) project a continuous greening of the planet during the 21 st century. To investigate the hydrological feedback from the projected Earth greening, we prescribed the increase in leaf area index (LAI) in the 21 st century as projected by CMIP5 ESMs into a state-ofthe-art ESM (IPCLCM), and simulated equilibrium climates for current CO 2 and LAI, an increase of CO 2 alone, an increase of LAI alone, and increases of both CO 2 and LAI, respectively. We find that the greening simultaneously intensifies evapotranspiration and precipitation over land. In terms of soil moisture content, the spatial difference between the responses of evapotranspiration and precipitation causes a hydrological response of the "dry gets drier, wet gets wetter" (DDWW) paradigm. Increasing LAI significantly decreases soil moisture content over dry regions, including the

Domaines: Milieux et Changements globaux

Jie Wu, Dashan Wang, Laurent Z.X. Li, Zhenzhong Zeng. Hydrological feedback from projected Earth greening in the 21st century. Sustainable Horizons, 2022, 1, pp.100007. ⟨10.1016/j.horiz.2022.100007⟩. ⟨hal-03862162⟩