AWESOME CGE scenarios and modelling outputs

The primary goal of this analysis was to study the impacts of climate change on food security given the potential supply of alternative water sources: desalination and reused (treated) water within the WEFE nexus in the Mediterranean Sea Basin. Accordingly, the first step of the analysis is to explicitly introduce desalination and treated water into the global CGE model and database. Using the standard GTAP model (Corong, Hertel, McDougall, Tsigas, & van der Mensbrugghe, 2017) and GTAP10A dataset (Aguiar, Chepeliev, Corong, McDougall, & & van der Mensbrugghe, 2019), the water sector was divided into three main categories using the SplitCom application (Horridge, 2008) and  including (a) natural water that refers to distribution of water, (b) desalinated water that refers mostly to seawater desalination and (c) treated water that refers primarily to wastewater and brackish water treatment. The resulting modelling framework is used as the basis of the second step, that assesses the externalities associated with the different water sources incorporated in the model.

To introduce alternative water sources in the CGE, several assumptions were made. First, desalinated water is produced from the abundant resource – seawater and therefore the scarcity value that is attributed to depletable natural resources is not applicable. Accordingly, desalinated water production can be treated as a sector disaggregated from the existing water sector in the GTAP database. For example, the economic activities of the desalination sector were reported as part of the water sector in input-output tables (United Nations, 2008).