Climate Change Information Fact Sheet: Ethiopia

Mean annual temperatures are around 15-20°C in these high altitude regions, whilst 25-30°C in the lowlands. Mean annual temperature has increased by 1.3°C between 1960 and 2006, an average rate of 0.28°C per decade. The increase in temperature in Ethiopia has been most rapid from July through September at a rate of 0.32°C per decade. Available data indicates that the average number of "hot" nights (the hottest 10% of nights annually) increased by 137 per year between 1960 and 2003, and "hot" days per year increased by 73. Future projections indicate that the mean annual temperature in the country will continue to increase. By 2030, the 10th, 50th, and 90th percentiles for the RCP4.5 model ensemble runs project increases of 0.44°C, 0.92°C, and 1.4°C, respectively. For the RCP8.5 ensemble, the corresponding increases are 0.61°C, 1.01°C, and 1.47°C. Maximum temperatures are projected to increase by 0.93°C to 0.98°C, and minimum temperatures by 0.93°C and 1.05°C for the RCP4.5 and RCP8.5 median model ensemble. Simple linear interpolation of projections indicate that annually, "hot" days will occur on 12-25% of days by the 2030s. Seasonal rainfall in Ethiopia is driven mainly by the migration of the Inter-Tropical Convergence Zone (ITCZ). Most of Ethiopia experiences one main wet season (called ‘Kiremt’) from mid-June to mid-September, when the ITCZ is at its northern-most position. Parts of northern and central Ethiopia also have a secondary wet season of sporadic, and considerably lesser, rainfall from February to May (called the ‘Belg’). The southern regions of Ethiopia experience two distinct wet seasons which occur as the ITCZ passes through this more southern position. The March to May ‘Belg’ season is the main rainfall season yielding 100-200mm per month, followed by a lesser rainfall season in October to December called ‘Bega’ (around 100mm per month). Future projections of mean annual rainfall averaged over the country from different models in the ensemble project a wide range of changes in precipitation for Ethiopia, but tend toward increases. By 2030, the RCP4.5 10th percentile (-23%), median (0.6%), and 90th percentile (28%) ensembles for mean annual precipitation indicate high uncertainty in the direction and amount of change across the models. These results are similar to RCP8.5 (-22%, 3.3%, and 33%). The median ensemble runs for RCP4.5 and 8.5 indicate an average annual rainfall increase of 0.1 to 0.2 mm/day by the middle of the 2030s. The weak response in country area-averaged precipitation masks important spatial patterns of precipitation change, as future precipitation (June-September) tends to increase over the Central Highlands and northern Great Rift Valley while decreasing over the southern part of the country, presenting a dipole pattern.