Elevated carbon dioxide (eCO 2 ) acts as a fertiliser for photosynthesis, driving an increase in gross primary production (GPP). However, it is unclear how effectively increased GPP propagates along the ‘carbon (C) cascade’ to increase net primary production (NPP) and vegetation C stocks ( C veg ) in different plant compartments. Vegetation models were criticised for being overly sensitive to photosynthesis (source‐driven), ne...

The Earth is greening in many regions under elevated atmospheric CO 2 concentrations, along with increasing temperature and land use changes. However, despite the continued rise in CO 2 , greening has stagnated or even reversed in some regions, suggesting a reduced capacity of the land surface to act as a carbon sink. Here, we show that declining water availability and rising atmospheric water demand have coincided with region...