Change in annual mean precipitation (mm)

Models of projected changes in temperature and annual mean precipitation of West Africa were commissioned by the Intergovernmental Panel on climate Change (IPCC). The scenarios predict temperature and precipitation for both the mid-21st century (2046-2065) and the late 21st century (2081-2100) relative to the late 20th century (1986-2005), based on two alternative greenhouse gas emission scenarios, RCP2.6 and RCP8.5 (RCP stands for Relative Concentration Pathways). Model projections based on these two extreme pathways are contrasted here, with RCP2.6 assuming that global greenhouse gas emissions peak between 2010 and 2020 and decline substantially thereafter, and RCP8.5 assuming that emissions continue to increase throughout the 21st century. The projections shown are multi-model averages. The averages tend to level out the considerable variability and disagreement between the individual models.  As the maps show, both scenarios predict a warming trend and predominantly positive changes in annual rainfall for most of West Africa. While most changes are small and insignificant, a wetter future is predicted for Niger and Chad, whereas the RCP8.5 scenario indicates a possible drying trend for the western part of West Africa.

These maps were reproduced for West Africa from data from the IPCC 5th Assessment Report (Niang and others, 2014).