An ensemble of models for identifying climate change scenarios in the Gulf of Gabes, Tunisia

Climate change is likely to increase the pressure on the environment and on human systems that are requiring new assessment tools aimed at supporting decision-makers and stakeholders towards a more sustainable and effective management of the coastal environment and its resources. This research appraises an ensemble of models that integrates complex interactions of climate and anthropogenic impacts on vulnerable Mediterranean coastal areas with application to the Gulf of Gabes, Tunisia. Starting from Global and Regional Circulation Models, the models' ensemble includes simulations of marine and atmospheric dynamics and biogeochemical processes in coastal waters under expected anthropogenic forcings, with a spatial domain ranging from subnational to local. In the case study area, the simulations showed that atmospheric temperature increase is likely to be around 4 degrees C in the summer months of 2100, relative to 1961-1990. In order to obtain the most reliable estimate of sea-level rate variations, satellite altimetry data have been processed over a period of 15 years (1993-2007) showing that sea-level changes on the Tunisian shelf were of the order of 2 mm/year. This value was considered as a reference for the sea-level change scenarios. As far as the water quality is concerned, the areas most impacted by pollution are located near major towns and human infrastructures, such as harbours. The set of results obtained by the proposed models' ensemble may be suitable for supporting a scientific dialogue with stakeholders and for the implementation of exposure scenarios supporting a regional risk assessment approach to the entire Gulf of Gabes area.