Water scarcity will increasingly be a challenge in the Arab countries. The Arab region has the lowest freshwater resource endowment in the world. All but six Arab countries (the Comoros, Iraq, Lebanon, Somalia, Sudan, and the Syrian Arab Republic) suffer from water scarcity, which is defined as having less than 1,000 m of water per person per year. It is estimated that climate change will reduce water runoff by 10 percent by 2050. Currently, the region suffers a water deficit (demand is greater than supply), and with increasing populations and per capita water use, demand is projected to increase further, by 60 percent, by 2045. Climate change will likely reduce agriculture production in Arab countries. This report is about climate change, its impacts on people and on the systems on which we depend, and how we might adapt to it. The text highlights a number of issues and areas that are being affected by climate change. One important message of the report is that climate change should be taken into account in all activities, including those not addressed in this report. Anticipation of climate change can be the stimulus for improving interventions, galvanizing support, and improving governance. This report can be used as a road map moving forward. This report seeks to provide, for the first time, a coherent assessment of the implications of climate change to the Arab region and the resultant risks, opportunities, and actions needed. The information highlighted within explains the potential impacts of climate change and the adaptation responses needed in key sectors and thematic areas, such as water, agriculture, tourism, gender and health, as well as in urban and rural settings. The report attempts to advance the discussion by providing adaptation guidance to policy makers in Arab countries.