Review of the Economic Impact of Water Availability on Food Security and the Related Ecosystems

Population growth, climate change, and technological development alter the concepts of water supply and demand, affecting both food security and ecosystem services. Groundwater withdrawal, seawater desalination, and wastewater treatment increase the water supply in water-stressed countries, while impacting marine, terrestrial, and croplands’ ecosystems and altering the prices of water and food. About 80% of the world’s wastewater is discharged untreated into biodiversity-rich freshwater and seawater, which is then being used to irrigate croplands and provide desalinated drinking water. Computable general equilibrium (CGE) and partial equilibrium (PE) are economic modeling approaches that aim to capture the multiple effects of the water–energy–food–ecosystem (WEFE) nexus on social welfare. In order to evaluate the combined effect of different types of parameters, the result of one or many PE models are fitted and feeding the CGE model. The aim of this chapter was to review recent work in assessing the impact of water quality and availability on food security and the related ecosystems. The review covers not only global aspects, but also considerations specific to the Mediterranean Sea basin, reviewing the methods to measure and quantify the potential change and the alternatives to manage it. The chapter provides a synthesis of key developments in the literature, identifies methodological gaps, and suggests research approach and policy solutions.