Summary:
Planning for future agricultural water needs remains challenging because climate and hydrological models can produce substantially different results. A study published in Communications Earth & Environment examined water requirements for eight major crops under multiple climate scenarios and investigated how differences between models influence projections of crop water demand and sustainability.
The researchers found that variability in end-of-century global estimates could reach about 18% for green water use, which depends on rainfall and soil moisture, and about 51% for blue water use, which relies on irrigation from surface water and groundwater. Variation was even greater for blue water sustainability, with estimates differing by several hundred percent depending on the model combination and emissions scenario.
The differences became larger at regional and local scales, particularly in agricultural areas already facing pressure on water resources. Hydrological models were the main source of variation in blue water assessments, while climate model differences had a greater influence on green water estimates, especially under high-emission scenarios.
The findings suggest that assessments of future agricultural water demand and sustainability should account for a range of model outcomes rather than relying on a single projection, particularly in regions where water resources are already under stress.
— Press Release —
Can we trust future estimates of crop water use and sustainability?
A new study reveals that uncertainties in global climate and hydrological models can dramatically alter estimates of future crop water use and water sustainability. The findings highlight the need for multi-model approaches to better guide agricultural water management in a warming world.
As climate change intensifies pressure on global water resources, accurately estimating future crop water needs and sustainability is becoming increasingly important for ensuring food security while preserving ecosystems. Yet global climate and hydrological models used to project future crop water demand and sustainability often produce substantially different results.
In the new study, published in Communications Earth & Environment and jointly led by PhD student Q. Sun and postdoctoral researcher F. Bassani, we quantified how uncertainty in global climate and hydrological models propagates into estimates of crop water use and sustainability. In the study, we adopted a multi-model ensemble approach to assess future water requirements and sustainability for eight major crops under multiple climate scenarios.
Results show that different climate and hydrological models can produce markedly different estimates of future crop water use and sustainability, with the largest uncertainty associated with irrigation-dependent blue water use. Model disagreement becomes even stronger at local to regional scales, particularly in agricultural hotspots already facing pressure on water resources, thus highlighting the difficulty of reliably assessing future water risks.
These findings highlight the need to move beyond single-model projections and adopt ensemble-based approaches that explicitly account for uncertainty. Recognizing and transparently communicating uncertainty is essential for producing more credible projections and supporting adaptive and resilient water management in a changing climate.
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Read the full publication here and explore the results at drop4crop!
Journal Reference:
Sun, Q., Bassani, F., Tuninetti, M. & Bonetti, S., ‘Uncertainties in global hydrological and climate models challenge future estimates of crop water use and sustainability’, Communications Earth & Environment online (2026). DOI: 10.1038/s43247-026-03621-w
Article Source:
Press Release/Material by CHANGE – Laboratory of Catchment Hydrology and Geomorphology | EPFL
Featured image credit: Ruud Peter Boelens | Pexels
