Yield improvements reduced global crop water footprint (1972–2018), but further action needed for water sustainability

Temporal variation in the water footprint (WF) of crop production has been less studied compared to spatial variation. This study assessed global spatiotemporal trends in the WF of crop production from 1972 to 2018 at 5 arcmin resolutions using a process-based crop model, alongside statistical analysis to identify key socio-economic drivers. The global WF increased from 4,799 km ³ in 1972 to 7,773 km ³ in 2018, with blue and green WFs rising by 65% and 62%, respectively, driven by growing demands for food, feed, biofuels, and other uses. Crop area expansion (40%) was the primary contributor, while increased crop productivity through land intensification helped offset further increases, preventing a near doubling of the WF. Green water accounted for 81% of the WF increase, emphasizing the need for better green water management. Oil crops, cereals, and fruits were the largest contributors to the WF rise. Population growth, livestock production, agricultural exports, GDP, and biofuel demand were identified as key drivers, offering insights into targeted strategies for sustainable water use in agriculture.