ABSTRACT
In spite of its geographical situation on the Atlantic and Mediterranean coast, Morocco is one of the most arid areas of the world; it experiences highly variable rainfall and recurrent droughts. The limited water resources are threatened by increasing demands and accelerated quality degradation. In addition, the Intergovernmental Panel on Climate Change (IPCC) predicts in its 4th Assessment Report that “Annual rainfall is likely to decrease in much of Mediterranean Africa and northern Sahara, with the likelihood of a decrease in rainfall increasing as the Mediterranean coast is approached” (IPCC 2007) Chapter 11, p. 866). The fact that climate is changing has become increasingly clear over the past decade. This prediction is based on several climate models that
simulate global and regional mean precipitation. While the multi-model predictions show confl icting results for some areas, in the Mediterranean and Northern Africa the multi-models show consistent results of signifi cant reduction in precipitation (IPCC 2007). The Intergovernmental Panel on Climate Change reports that heat waves have been increasing towards the end of the 20th century and are projected to continue to increase in frequency, intensity and duration worldwide (WHO 2009; Baccini et al. 2008; IPCC 2007; Meehl et al. 2007; Robinson 2001). Climate change is caused by the combined impact of growing human population and economic activities (WHO 2003b). The IPCC has developed a series of 40 scenarios of plausible future trajectories for population growth, economic and technological development (IPCC 2000). Each scenario gives estimates for greenhouse gas emission levels, and predicts the changes in the temperature ( Campbell-Lendrum and Woodruff 2007). For example, temperature may be estimated to increase by 0.54C (scenario B2 – low emission scenario), 0.84C (scenario A1B – middle emission scenario) or 1.02C (scenario A2 – high emissions scenario) in 2030, relative to the baseline period (WHO 2009).
