Key trends and opportunities in water footprints of crop production

Crops consume the majority of green and blue water worldwide which, in many areas, affects water availability and state of ecosystems. Hence, it is important to understand the recent dynamics in crop water footprints (WF, m³ t^-1). Here, we analyse the global WF of more than 150 crops during 1990–2019 simulated with a global gridded crop model ACEA at 5 x 5 arc minute resolution. Our results indicate the overall decreasing trends in unit WF across all crop groups. However, these reductions are insufficient to curb the increase in total water consumption, which is mostly driven by the growing demand for oil crops. The WF dynamics vary among regions due to a combination of multiple environmental and socio-economic factors. Thus, it is possible to identify key challenges and opportunities in WFs of crop production. Addressing them may benefit water and food security while making the global food system more sustainable.