Spatial vulnerability assessments are useful tools for understanding patterns of vulnerability and risk to climate change at multiple scales. The demand for vulnerability maps among development agencies and governments is increasing as greater emphasis is placed on scientifically sound methods for targeting adaptation assistance. Such mapping is useful because climate variability and extremes, the sensitivity of populations and systems to climatic stressors, and adaptive/coping capacities are all spatially differentiated. The interplay of these factors produces different patterns of vulnerability. This climate vulnerability mapping study seeks to illuminate the economic, social, and natural systems in West Africa that will be exposed to future sea-level rise, storm surge, and riparian floods. It covers the Guinea Current countries, extending from Guinea-Bissau in the northwest to Cameroon in the southeast. Although all 10 countries are exposed to seaward impacts, the coastal fringe from Côte d’Ivoire to Nigeria is a relatively low-lying region of rapid population growth and intense economic development and, as such, is particularly vulnerable to future surge and sea-level-rise impacts. In this study, the coastal zone is defined as a 200 kilometer strip from the coastline inland. The areas covered are somewhat larger than what might normally be construed as “coastal,” but we have included a larger area in recognition of the fact that the economic impacts of climate change in the coastal zone will not be confined to the coastline itself, but will extend further inland. This is especially the case if one considers not only direct impacts but also secondary impacts on livelihoods and economies tied to coastal cities. Almost half of the region’s population—24 million people—live in this 200 kilometer strip. CIESIN used best available data on coastal elevation—the Altimeter Corrected Elevations 2 (ACE2) data set—and flood risk to identify areas at potential risk of inundation from sea-level rise, surge, or river-bank flooding. CIESIN also created two composite indices (one representing social vulnerability and another representing economic systems), projected the population of the region to 2050, and examined the natural systems that will be exposed. This report includes a brief review of coastal-climate exposure and the data available to measure it (Section 2.0), and then proceeds to a broader description of data and methods for the exposed systems (Section 3.0) followed by results (Section 4.0). Section 5.0 provides overall conclusions. Data descriptions (map metadata) for each of the data sets used in this study are provided in Annex 1.

The reports and maps were produced by CIESIN, Columbia University, under contract with Tetra Tech ARD for the United States Agency for International Development Task Order under the Prosperity, Livelihoods, and Conserving Ecosystems (PLACE) Indefinite Quantity Contract Core Task Order (USAID Contract No. AID-EPP-I-00-06-00008, Order Number AID-OAA-TO-11-00064).