Impact of climate change and El Niño episodes on droughts in sub-Saharan Africa

Abstract

Various drought prone regions of sub-Saharan Africa (SSAF) have been affected by severe droughts in recent decades and centuries, which had caused catastrophic humanitarian crisis. In this study, the Palmer Drought Severity Index was used to analyse changes in drought characteristics of SSAF during 1971–2000 and the Representative Concentration Pathways (RCP4.5 and RCP8.5) climate projections of selected GCMs (Global Climate Models) for the 2041–2070 (2050s) and 2071–2100 (2080s) periods. The results show that most areas in South Africa (SA) and West Africa (WA) will shift to a drier climate in the 2050 and 2080s. However, some areas in Greater Horn of Africa (GHA) are expected to be relatively wetter in the 2050 and 2080s whereas very little change is projected in the average drought severity of Central Africa (CA). The frequency of short (6–12 months) and long (above 12 months) drought events also increased on average by 5 %. However, a 1–6 % decrease in the average duration of long drought periods was projected during the 2050 and 2080s likely due to the increase in the intensity and frequency of extreme precipitation events in SSAF. An increase in the frequency of El Nino episodes under a warmer twentyfirst century climate is also expected to increase the drought prone regions of WA, SA and particularly GHA while CA still remains virtually unaffected. Overall, the results suggest that SSAF will experience a drier climate in the 2050 and 2080s with an increase in drought prone areas in the four corners of the sub-continent.