In the long term, will there be water shortage in Mediterranean Europe?

Abstract

The European Mediterranean countries may seem to be less exposed to water scarcity risks in the future than their Southern and Eastern neighbours. But these risks cannot be excluded, so we should be concerned and make an appropriate assessment in order to be prepared to face them. This chapter tries to explore on a long term basis looking towards a 2050 horizon the possible changes in water resources and water demands of these countries in order to estimate the possible tensions and imbalances, their location and their degree of seriousness. Structural or cyclical, regional or local, water shortage demonstrates breaks in the balance between supply (linked to the resources and the state of their mobilisation) and the demand (of all utilisation sectors), whether these breaks occur from insufficiency or a breakdown in resources or from water production or too much demand. Therefore, the long-term forecast consists in understanding the occurrences of shortages -and envisaging where and when they could appear- on the basis of the examination and comparison of assumed future developments, according to various theories, supplies -first of all conventional water resources- and demands within the framework and timeframe considered, i.e. Mediterranean countries of Europe, the first half of the 21s1 century. Resources, like demand, are subject to change and variation, depending on dynamics that are often very different. But comparing them is only meaningful within a temporally and spatially relevant framework, i.e. a too extensive field may hide local imbalances; a too- restricted field may not be appropriate for the definition of resources and reduce the possibilities of transporting water. In the countries considered as the most extensive (France, Greece, Italy and Spain), the most appropriate fields are catchment areas or groups of catchment areas. The long-term forecast implies first of all analysing the initial conditions, i.e. the stress between mobilisable resources and demands which indeed exists right now in a few regions and overshadow the future. An exploration of future demands will be attempted, taking into account that, in the long term, it is easier to predict certain factors, in particular population, than total quantities directly. The effects of climatic changes on resources, despite the still considerable uncertainties that affect forecasting, cannot be avoided.