Future socioeconomic development along the West African coast forms a larger hazard than sea level rise

Sea level rise will exacerbate the vulnerability of low-lying coastal regions around the world in the coming decades, posing a severe threat to coastal populations. Here, we assess the future population and asset exposure of West Africa (WA) to normal and extreme coastal flooding based on the projected sea level rise scenarios reported in the IPCC Sixth Assessment Report using a bath tub modeling approach, MERIT DEM and gridded population gross domestic product datasets that are consistent with the Shared Socioeconomic Pathways. We find that socioeconomic development will be responsible for the maximum increase in future coastal flooding along the WA coast towards the end of the century. While contributions from climate-induced sea level rise will dominate and be responsible for changes in coastal flooding events in some countries, exposure to these events is likely to dominate in many countries if the ongoing horizontal infrastructural development and economic-oriented transformation continue. These results have important implications for both sustainable coastal planning and flooding risk mitigation for WA’s coastal areas and should be considered as a cautionary tale for managing increasing socioeconomic development and coastward migration at the expense of the region’s coastal ecosystems.

Oleseun A. Dada, Rafael Almar, Pierre Morand, Erwin W. J. Bergsma, Donatus B. Angnuureng, Philip S. J. Minderhoud