Discriminating climate impacts between 1.5 • C and 2 • C warming levels is particularly important for Central Africa, a vulnerable region where multiple biophysical, political, and socioeconomic stresses interact to constrain the region's adaptive capacity. This study uses an ensemble of 25 transient Regional Climate Model (RCM) simulations from the CORDEX initiative, forced with the Representative Concentration Pathway (RCP) 8.5, to investigate the potential temperature and precipitation changes in Central Africa corresponding to 1.5 • C and 2 • C global warming levels. Global climate model simulations from the Coupled Model Intercomparison Project phase 5 (CMIP5) are used to drive the RCMs and determine timing of the targeted global warming levels. The regional warming differs over Central Africa between 1.5 • C and 2 • C global warming levels. Whilst there are large uncertainties associated with projections at 1.5 • C and 2 • C, the 0.5 • C increase in global temperature is associated with larger regional warming response. Compared to changes in temperature, changes in precipitation are more heterogeneous and climate model simulations indicate a lack of consensus across the region, though there is a tendency towards decreasing seasonal precipitation in March-May, and a reduction of consecutive wet days. As a drought indicator, a significant increase in consecutive dry days was found. Consistent changes of maximum 5 day rainfall are also detected between 1.5 • C vs. 2 • C global warming levels.

This study examines the potential impacts of climate change on the characteristics of precipitation over the Drakensberg Mountain Range (DMR) at different global warming levels (GWLs: 1.5, 2.0, 2.5 and 3.0°C) under the Representative Concentration Pathway 8.5 (RCP8.5) scenario, using dynamical and statistical downscaled datasets. The dynamical datasets consist of 19 multi‐model simulations datasets from the Coordinated Regional Climate Downscaling Experiment (CORDEX), whereas the statistical downscaled datasets comprise 19 multi‐model simulations from the National Aeronautics and Space Administration (NASA) Earth Exchange (NEX) Global Daily Downscaled Projections (NEX‐GDDP, hereafter NEX). The capacity of the CORDEX and NEX datasets to represent past characteristics of extreme precipitation over the DMR was evaluated against eight observation datasets. The precipitation characteristics were represented by eight precipitation indices. Both CORDEX and NEX realistically capture the characteristics of extreme precipitation over the Drakensberg and, in most cases, their biases lie within the observation uncertainty. However, NEX performs better than CORDEX in reproducing most of the precipitation characteristics, except in simulating the threshold of extreme rainfall. The ensemble means of CORDEX and NEX agree on a future increase in the intensity of normal precipitation, in the frequency and intensity of extreme precipitation, as well as an increase in widespread extreme events, with a decrease in the number of precipitation days and continuous wet days. However, they disagree on the projected changes of annual precipitation, for which CORDEX projects an increase over most parts of the DMR, whereas NEX indicates a decrease. The self‐organizing‐map analysis, which reveals diversity in the projection patterns hidden in the ensemble means, shows the most probable combinations of projected changes in the annual precipitation and extreme precipitation events (in terms of intensity and frequency): (a) increase in both annual precipitation and extreme precipitation events; (b) decrease in both annual precipitation and extreme precipitation events; (c) decrease in annual precipitation but increase in extreme precipitation events. The results of this study can thus provide a basis for developing climate change adaptation and mitigating strategies over the DMR.

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This study investigates the characteristics of widespread extreme rainfall events (WERE) over the Drakensberg with the aid of observation, reanalysis, and simulation data during the period 1987–2016. WERE event over the DMR was defined as a rainfall event during which at least 40% of the grid points over the DMR experienced at least 95% percentile of daily rainfall at the respective grid points. The simulations were performed using the Weather Research and Forecasting (WRF) model and the Model for Prediction Across Scales (MPAS). The capacity of the WRF and MPASS models to represent past characteristics of extreme precipitation over the DMR was evaluated against five observation datasets and the forcing reanalysis data. Precipitation characteristics were represented with four precipitation indices. Both models (MPAS and WRF) simulate realistic rainfall characteristics over Southern Africa, especially over South Africa and DMR. For all the precipitation indices, the models capture the west-east precipitation gradient over South Africa and reproduce the local precipitation maxima over the DMR as well as along the south and southeast coasts of South Africa. Nevertheless, there are notable differences in the performance of the models. While MPAS performs better than WRF in some cases, WRF performs better than MPAS in other cases. All the observation datasets agree that WERE mostly occurs in three seasons over DMR and does not occur every year. However, there are substantial disagreements among the datasets regarding the climatology and annual frequency of WERE. Self-organizing map analysis of grid points where extreme rainfall occurred during WERE events shows that there are 5 major spatial patterns of strong rainfall areas during WERE events over the Drakensberg. The patterns are generally associated with frontal systems, tropical temperate troughs, and ridging highs. Patterns of strong rainfall areas during WERE events identified in this study could help in the management of extreme rainfall-related disasters around the Drakensberg.