Climate change in the Mediterranean may reduce water resources, increase irrigation demand

Worsening climate conditions are expected to threaten water supplies in the Mediterranean region and its agricultural systems, which rely extensively on irrigation.

A profound understanding of the effect of climate change on crop water consumption and irrigation requirements is crucial to better manage water resources, particularly in regions largely affected by water scarcity with aggravating conflicts between water-demanding sectors.

In the study "A modelling platform for climate change impact on local and regional crop water requirements", an international team of scientists led by the CMCC Foundation – Euro-Mediterranean Center on Climate Change in collaboration with the IHE Delft Institute for Water Education, UC Davis, and the University of Sassari elaborated assessments of crop consumption and irrigation requirements under future climatic conditions. The results provide guidelines for precision agriculture at a local scale and help evaluate requirements at a larger scale. This couples big data with climate projections to support climate change adaptation policy planning.

The research shows that in Mediterranean countries, maize, wheat, and grape production will require on average 13%, 16%, and 10% more water, respectively, during 2035-2065 and under the climate scenarios RCP 8.5 and RCP 4.5. The RCP 8.5 indicates a scenario of comparatively high greenhouse gas emissions, and RCP 4.5 an intermediate scenario that assumes imposition of effective emissions mitigation policies. At the same time, as a result of more pronounced future droughts, a general yield decline is expected, especially for staple crops such as maize and wheat. Increases in irrigation demand and reduction in water supplies due to climate change, can lead to significant challenges for water resource management to reduce conflicts among sectors (e.g. household use, energy production, tourism, industrial production processes) for water use.

Increasing the resilience of the agricultural sector to extreme events in Mediterranean countries through adaptation and mitigation strategies is a critical priority for governments. It implies optimizing water consumption while also supporting food security.

The study developed and tested two new implementations of the Simulation of Evapotranspiration of Applied Water model (SIMETAW#), and confirmed the importance of such modelling tools to help farmers and policymakers. It ultimately aims at developing optimal strategies balancing economic growth and environmental sustainability by addressing water demand vs. available supplies at different spatial scales.

Water resource planning in the current and future climate requires a strong multidisciplinary and transversal approach to ensure the availability of scientifically-based information on irrigation needs and the different management options at various scales."

Donatella Spano, Senior Member of the Strategic Council of the CMCC, one of the authors of the article

"To accelerate the achievement of the Sustainable Development Goals, policies and strategies should be developed by assessing interlinkages, synergies, and trade-offs between the various sectors" said Sara Masia, CMCC researcher. "This integrated approach can support policymakers in the different sectors to make decisions on the environment, resources security, and economy, and to develop plans and strategies targeted to sustainable integrated resource management".