Sustained global greening driven by continuous CO2 fertilization

Abstract Global greening and browning, as evidenced by changes in leaf area index (LAI) derived from satellite observations, indicate how ecosystems respond to rising atmospheric CO 2 , climate change, and human interventions. However, uncertainties in satellite LAI records have led to conflicting conclusions about global trends and their drivers. Here, by developing a refined Advanced Very High-Resolution Radiometer LAI dataset with reduced radiometric and geometric uncertainties, we find a sustained global greening during 1982–2021 (0.035 m 2  m –2 decade –1 ). Global greening is largely driven by the continuous CO 2 fertilization (1982–2001: 72%; 2002–2021: 77%), while land-use management determines regional patterns. An ensemble of 15 Earth system models also simulates persistent greening (0.050 ± 0.044 m 2  m –2 decade –1 ), but fails to reproduce the observed spatial patterns of greening and drivers. These findings provide observational evidence for sustained global greening, with no clear signs of slowing CO 2 fertilization effect under current CO 2 and climatic conditions.