Assessment of Historical and Future Mean and Extreme Precipitation Over Sub-Saharan Africa Using NEX-GDDP-CMIP6: Part II—Future Changes

This study utilised a multi-model ensemble (MME) of 26 NASA Earth Exchange Global Daily Downscaled Projections (NEX-GDDP) to assess future changes in mean and extreme precipitation over sub-Saharan Africa at both seasonal and annual scales under three Shared Socioeconomic Pathway scenarios: SSP1-2.6, SSP2-4.5, and SSP5-8.5. The changes are examined for two distinct future periods, specifically the near future (2031–2060) and the far future (2061–2090), relative to 1985–2014. Nine precipitation indices are utilised to characterise extreme precipitation. The results show that mean precipitation is expected to increase in northern sub-Saharan Africa, while a decrease is expected in the southern region. Additionally, the duration of dry spell (CDD) is expected to decrease, while the duration of wet spell (CWD) and precipitation frequency (RR1) are projected to increase in the northern region. Conversely, CDD is expected to increase, and CWD and RR1 are expected to decrease in the southern region. These trends become more pronounced in the far future compared to the near future, particularly under the high-emission scenario SSP5-8.5. However, there are few localised regions where at least 80% of the models agree with the MME on the changes in CDD, CWD and RR1 under all scenarios for both time frames. Precipitation intensity is expected to increase across most of sub-Saharan Africa in both time frames, regardless of the scenario, leading to more frequent heavy precipitation and extreme wet events. This increase is expected to be more pronounced under the SSP5-8.5 scenario, particularly in the far future. Specifically, at least 80% of the models project an increase in heavy and extreme wet events across most of northern sub-Saharan Africa under all scenarios for both time frames. These findings emphasise the urgent need to develop effective adaptation strategies for sub-Saharan Africa to mitigate the potential impacts of these projected changes in precipitation characteristics.

SAMUEL Sydney;  TSIDU Gizaw Mengistu;  DOSIO Alessandro;  MPHALE Kgakgamatso; 

2026-01-26

WILEY

JRC141234

1097-0088 (online),   

https://rmets.onlinelibrary.wiley.com/doi/abs/10.1002/joc.70179,    https://publications.jrc.ec.europa.eu/repository/handle/JRC141234,   

10.1002/joc.70179 (online),