The potential implications of climate change are greatest in areas with dense populations and associated economic activities, such as low-lying coastal cities. Few, if any, African coastal cities are prepared to deal with the impacts of climate change, particularly sea level rise and storm events.
African coastal cities are characterized by rapid and unplanned growth, high population concentrations, and overburdened infrastructure, all of which will influence the extent of any possible consequences caused by changes in extreme water levels in the twenty-first century. Most of the African coastal cities currently face significant threats from direct and indirect impacts of climate variability and change. Despite these threats, few coastal cities have been assessed for potential coastal impacts.
Sea level rise threatens infrastructure, coastal agriculture, key ecosystems and fisheries at risk. Concern about all these effects of the changing climate and rising sea levels is apparent. This chapter, therefore, provides a broader understanding of the potential hazards and anticipated impacts on most African coastal systems and cities based on physical exposure and socio-economic vulnerability to climate extremes and sea level rise.
The West, Central, East, and Mediterranean coastal regions make up the majority of Africa’s coastline zone, which is also quite low-lying. Several cities like Dakar, Abidjan, Accra, Lomé, Cotonou, Lagos, Douala, Dar es Salaam, Maputo, Durban, Cape Town, Alexandria, Tripoli, and Tunis, are located within these coastal zones. These coastal cities are characterized by a thriving population and industry, an extensive range of coast-based tourist destinations, and a dense network of transport and communication link.
The coastal zone encompasses some of the planet’s largest and most heavily populated megacities, along with some of the fastest-growing urban regions. It is important to note that the population density in many coastal regions is quite low. The majority of individuals reside in smaller towns and settlements that are situated along subsiding coastlines and in river deltas.
It is essential to acknowledge the undeniable fact that the impact of climate change on the coastline is far-reaching and affects numerous people, economic activity, and critical infrastructure. One must not forget that around 23–37% of the world’s population resides within 100 km of the shore, implying that they are susceptible to these impacts, whether directly or indirectly.
The coastal zone features valuable ecosystems and larger population concentrations than inland areas. Moreover, it contributes significantly to national wealth.
Sea-level rise (SLR) has far-reaching consequences for low-lying coastal communities and beyond. The direct impacts of SLR can be quite severe, including flooding of low-lying areas, erosion of coastlines, destruction of coastal wetlands, infiltration of saltwater into freshwater sources, higher groundwater levels, and elevated water levels that can cause coastal flooding Human-induced pressures on the coastal zone (such as population growth, subsurface fluid abstraction, and changes in the hydrological regime, including damming) will exacerbate the effects of sea-level rise.
Widespread erosion and flooding are currently ravaging large areas along the African coast, resulting in significant ecological issues as well as a high level of human misery.
In many places, the phenomenon of subsidence and coastal erosion may also exacerbate the effects of the SLR. Other socioeconomic effects include the destruction of human settlements, the displacement of port and navigational infrastructure, and the disruption of the coastal fishing and tourism-based industries. The already struggling African economy would be subjected to intolerable pressure from these negative consequences.
A Guest Editorial