Future Drought index: Ensemble 10th,50th and 90th percentiles of Annual standardised precipitation evapotranspiration index: A drought measure specified using precipitation and evaporation (SPEI) for baseline period of 1961-1991

The climate extremes projections over the Free State Province were conducted using the Coupled Global Climate Models (CGCMs) of the Coupled Model Intercomparison Project Phase 6 (CMIP6) datasets as part of the Assessment Report (AR) 6 of the Intergovernmental Panel on Climate Change (IPCC). The focus was on climate extreme events including heat, drought, heatwaves, and flooding. Calculations of climate extreme indices that speak to the identified extreme events were conducted using 10 CMIP6 climate models from the Inter-Sectoral Impact Model Intercomparison Project (ISIMIP) community. The ISIMIP models were statistically downscaled using the CMIP6 climate model scenario 4, Shared Socioeconomic Pathways 3-70 (SSP3-7.0), also known as the regional rivalry scenario, in the context of the Paris Agreement temperature goals. Under this scenario, a resurgence of nationalism and regional conflicts overshadow global issues. Governments increasingly prioritize national and regional security, leading to reduced investments in education and technological development. Inequality grows, and some regions experience severe environmental damage. These extreme indices were selected from the 27 core indices developed by the World Meteorological Organization (WMO) Expert Team on Climate Change Detection and Indices (ETCCDI) widely used for analysing extreme events in a changing climate. The calculations were conducted for the baseline period (1961-1990). The level of model uncertainty was represented by ensemble percentiles (10th, 50th and 90th percentiles) from the 10 models in which agreement between the models on the projected spatial pattern of the monthly maximum value of daily maximum temperature (Txx) for the baseline period is illustrated.