<p>This study assesses tropospheric black carbon (BC) particulates in West Africa from 1980 to 2024, focusing on source apportionment, emission trends, residence time, and transport mechanisms using MERRA-2 datasets. The findings highlight a significant rise in BC concentrations and emissions, especially between the late 1990s and early 2000s. Biomass burning emissions peaked in 1998 at 1.99E-12 kg/m²/s, while anthropogenic emissions increased from 6.25E-13 kg/m²/s in 1980 to 1.05E-12 kg/m²/s by 2024. The temporal variability in biomass burning emissions reached a maximum of 22.48 kg/m²/s in the late 1990s before stabilizing. The residence time analysis reveals distinct trends for BC components. Sedimentation (BC S-1 and BC S-2) residence times decreased from 0.709/0.704 days (1980–1989) to 0.739/0.681 days (2020–2024). Hydrophobic-hydrophilic BC (BC Hphi-O) residence time increased from 0.003 days (1980) to 0.004 days (2024). BC transport and deposition patterns improved over the years, with average wet deposition at 6.59E-13 kg/m²/s and dry deposition at 1.82E-13 kg/m²/s. Pearson correlation analysis indicates strong correlations for anthropogenic BC emissions (r² = 0.8803), moderate correlations for BC CS-2 (r² = 0.7868) and BC S-2 (r² = 0.7127), and weaker associations for biomass burning BC (r² = 0.377). Dendrogram analysis identifies biomass burning and anthropogenic activities as primary contributors to rising BC concentrations. The results underline the significant role of these emissions in increasing BC levels, suggesting prolonged atmospheric persistence of certain BC components, which may exacerbate climate change and pose public health risks. The study emphasizes the need for policy-making, monitoring, and collaboration among ECOWAS member states to control biomass burning and industrial emissions, mitigating climate and health impacts</p>