Biophysical effects of land cover changes in West Africa: a systematic review

Abstract

West Africa is undergoing rapid agricultural intensification driven by population growth, leading to significant anthropogenic land use and land cover change (LCC), including both deforestation and afforestation. These changes can profoundly affect the regional climate system by altering the surface energy balance, moisture fluxes, and atmospheric circulation, potentially exacerbating the vulnerability of human, ecological, and economic systems. Despite the ability of climate models to simulate LCC impacts, considerable uncertainties remain, particularly in simulations of precipitation and temperature responses. This study provides the first multidisciplinary systematic review of LCC impacts in West Africa. Data from 26 selected publications were eventually synthesized from an initial pool of nearly 6000 studies. Results indicate that deforestation generally contributes to regional warming, with significant historical temperature increases of +0.26 ± 0.12 ◦C and projected increases of +0.88 ± 0.25 ◦C under the future scenarios. Conversely, afforestation could have significantly cooled the climate, lowering temperatures by −0.24 ± 0.14 ◦C historically and −0.22 ± 0.14 ◦C in future scenarios, without even accounting for carbon sequestration. Deforestation decreases regional precipitation by 80 ± 58 mm yr−1 historically and −55 ± 102 mm yr−1 in future scenarios, while large-scale afforestation could substantially reduce droughts with increased precipitation, averaging +40 ± 67 mm yr−1 historically and 80 ± 58 mm yr−1 in future scenarios. These results emphasize the need to integrate LCC-induced climate effects into land-based mitigation strategies, climate policy, and assessment frameworks.