Purpose – To assess the extent of climate change likely to be manifested in the MENA region using statistical tools as well as outputs from physics-based General Circulation Models (GCMs). The application of two diverse approaches and their comparisons should develop greater confidence and understanding of the climate change process among water resources planners and practitioners to respond judiciously in adopting mitigation and adaptation measures. Design/methodology/approach – Atmospheric temperature and precipitation primarily capture climate change features and are considered the drivers of other manifestations of climate change such as rises in sea-level, tropical cyclone intensities, severe floods, prolonged droughts, and retreating ice. Data on atmospheric temperature and precipitation have been statistically analysed for trend, distribution and variability in this study. Long-range prediction is then made using time series analysis. Long-range projections have also been made by many investigators using physics-based GCMs and the Fourth Assessment Report of IPCC provides a summary. IPCC projections are not indisputable because of some inherent limitations of GCMs. A comparative study is made between statistical predictions and IPCC projections, as well as forecasts from some GCMs specifically applied to the region, to develop a more reliable forecast scenario. Water resources projects are quite vulnerable to changes in atmospheric temperature and precipitation amounts. The various aspects of planning, design and management of water resources projects which are likely to be influenced by climate change are discussed. Findings – There is considerable variability in atmospheric temperature and precipitation in recent observations but if the variability is filtered out and the underlying trend extrapolated it is found that there is in general an agreement between IPCC projections and statistical predictions. For rise in atmospheric temperature projections made from many GCMs applied to the region, as well as projections summarised in the Fourth Assessment Report of IPCC, appear to be good estimates to be included in design considerations. For precipitation, statistical predictions are perhaps a better choice because GCM projections are less reliable with precipitation since associated meteorological processes occur at a much smaller scale than the grid size of a GCM. For low-lying coastal regions sea-level rise and more frequent extreme climatic events such as tropical cyclones add to the dimensionality of design considerations especially for infrastructure design. Originality/value – This paper presents a comparative study of possible climate change in the long-term between physics-based model projections and statistical predictions. This should provide greater insight into climate change that is expected in MENA and reduce uncertainty, thereby instilling greater confidence in water resources planners and practitioners to incorporate climate change aspects into decision making. This research is believed to be particularly helpful because of scanty research work done on this part of the globe on climate change.