Current and future evolution of drought risk in Ethiopia: A framework to inform disaster risk reduction and climate change adaptation policies

Climate change is projected to increase the frequency and intensity of future droughts particularly affecting the most low-income countries directly dependent on local rainfed food security and livelihoods. Drought risk and its related impacts depend on the drought hazard, the exposure and the vulnerability of the different socioeconomic sectors and/or ecosystems as well as the adaptive capacity of affected locations. The Horn of Africa, which includes Ethiopia, is currently experiencing one of the most severe droughts in the last 40 years. This study applies a storyline approach to investigate changes in drought risk for Ethiopia combining vulnerability, hazard and adaptive capacity information for current and future projected climatic and socio-economic conditions using a subnational level composite indicator. For our analysis, we define drought based on the Standardised Precipitation-Evapotranspiration Index (SPEI) which characterises the deficits in local water availability based on the precipitation and potential evapotranspiration. SPEI is computed using bias corrected Inter-Sectoral Impact Model Intercomparison Project (ISIMIP) project based on the Coupled Model Intercomparison Project Phase 6 (CMIP6). The Drought vulnerability assessment is carried out combining exposure, adaptive capacity and sensitivity indicators, using INFORM index developed by the Joint Research Centre of the European Commission to support humanitarian crisis and disaster decision-making. The analysis shows that future drought will increase people in need of food assistance both under current population and future population projections. If humanitarian aid and assistance are maintained at recent historical levels, these findings show a substantial increase in the required amounts. These conditions are exasperated when humanitarian access is impeded by local conditions such as the current conflict in Ethiopia, when imports are reduced by crises such as those associated with the Russian invasion of the Ukraine, and by pandemics such as COVID-19. Climate change mitigation is shown to reduce the vulnerability of Ethiopia through a reduction in drought hazard frequency and intensity. The framework presented in this study can be used as a policymaking tool to provide information on how to better prioritize future loss and damage funds and adaptation and mitigation investments to reduce population vulnerability and exposure.