Author(s): Lelia Croitoru, Juan José Miranda and Maria Sarraf
Affiliated organization: World Bank
Type of Publication: Article
Publication Date: March 2019
West Africa’s coastal areas host about one third of the region’s population and generate 56 percent of its GDP. They are home for valuable wetlands, fisheries, oil and gas reserves, and high tourism potential. However, these areas are affected by severe pressures: rapid urbanization along the coast has increased the demands on land, water, and other natural resources; man-made infrastructure and sand extraction have contributed to significant coastal retreat; moreover, climate change and disaster risks are exacerbating these threats. As a result, coastal areas are undergoing alarming environmental degradation leading to deaths (due to floods, air and water pollution), losses of assets (houses, infrastructure) and damages to critical ecosystems (mangroves, marine habitat).
This study covers four countries—Benin, Côte d’Ivoire, Senegal, and Togo—with a total population of 56 million people and a coastline of 3,400 km. The coastal areas of these countries—defined as all districts along the coast —are home to 36 percent of the countries’ total population. The four countries were selected due to better data availability on coastal issues compared to other countries of the project, given by the multi-hazard risk assessment of the International Marine & Dredging Consultants (IMDC), multi-sectoral investment plans, national statistics, etc.
This study estimates in monetary terms the Cost of Environmental Degradation (COED) in these areas. Specifically, it values the impacts of degradation that occur during one year, as a result of three major factors: flooding, erosion, and pollution (from water, air and waste). The final results are expressed in 2017 prices. They are reflected in absolute (US$) and in relative terms, as percentage of the countries’ GDP. Overall, estimating the COED in monetary terms will provide an indication of the real magnitude of damage and of the urgency of action needed to protect the coastal areas.
Overall, the COED of the four countries is estimated at about US$3.8 billion, or 5.3 percent of the countries’ GDP in 2017. Flooding and erosion are the main forms of degradation, accounting for more than 60 percent of the total cost. Moreover, coastal degradation causes over 13,000 deaths a year, primarily due to air and water pollution, and to floods. At the country level, coastal degradation imposes costs varying between 2.5 percent of GDP in Benin to 7.6 percent of GDP in Senegal in 2017.
These estimates are the result of three major factors affecting the coastal area:
- Flooding due to high rainfalls (pluvial floods) and overflowing rivers (fluvial floods) causes deaths and leads to major damage to houses, infrastructure and critical ecosystems, such as beaches and mangroves. Floods are extremely damaging in Côte d’Ivoire, costing society US$1.2 billion per year, mainly due to large areas affected by pluvial floods. In the other countries, flooded areas and the associated water depths are smaller, leading to comparatively lower flooding costs. West African countries are severely affected by floods. Flood frequency has increased in the past 50 years and are expected to increase in the future (Niang et al., 2014).Cost of Coastal Flooding: When translated into socioeconomic and environmental terms, coastal floods affect livelihoods (forgone economic activity), public and private assets (infrastructure, businesses and properties), welfare (injuries, drowning, psycho-physical stress, migration, coping, social dislocation, etc.) and ecosystem services. Adding up the damages to assets, economic production and mortality, the total cost of floods in coastal districts is estimated between US$10 million in Togo to US$1.2 billion in Côte d’Ivoire. This corresponds to a range between 0.2 percent and 2.9 percent of the countries’ GDP. Overall, damages due to flooding account for US$1.45 billion, or 2.1 percent of the four countries’ GDP.
- Coastal erosion is a major environmental problem throughout West Africa. Globally, 24 percent of coastal areas are eroding at rates exceeding 0.5 m per year (Luijendijk et al., 2018). Erosion is a result of both natural and human factors. Some areas have no erosion at all, others have land losses (erosion), and others have land gains (accretion). West African coastal areas are further exposed to erosion due to higher population growth and migration to coastal areas, concentration of economic activity39, and sea level rise. About 56 percent of the coastline in Benin, Côte d’Ivoire, Senegal and Togo is subject to an average erosion of 1.8 meters per year. Erosion is the most damaging factor in Benin, Senegal, and Togo, primarily due to losses of high value urban land.Cost of Erosion: The total cost of erosion is estimated between US$97 million in Côte d’Ivoire and US$537 million in Senegal. Overall, the cost of erosion in the four countries is US$964 million, or 1.4 percent of their GDP. In all countries, the cost of erosion is expected to increase considerably in the future, as the phenomenon is likely to affect larger urban areas.
Flooding due to high rainfalls (pluvial floods) and overflowing rivers (fluvial floods) causes deaths and leads to major damage to houses, infrastructure and critical ecosystems, such as beaches and mangroves
- Pollution from air, water and waste mismanagement imposes an important toll on people’s health and quality of life. It can reach as high as US$0.7 billion, in Côte d’Ivoire. In all countries, unsafe water, sanitation, and hygiene are particularly harmful, causing more than 10,000 deaths per year; they affect primarily Côte d’Ivoire and Senegal, with more than 4,000 deaths per country. Air pollution and waste mismanagement are also important forms of degradation but are considerably underestimated: the cost of air pollution (2,500 deaths) refers only to the impacts of fine particulate matter in the countries’ capitals, while the cost of waste covers only the effects of insufficient collection and inappropriate disposal of municipal waste.
Air: Overall, ambient air pollution on West African coastal areas is a problem that risks to be aggravated in the future. Although the present estimates refer only to four cities—the only ones for which measurements or estimations could be found—other urban areas also experience harmful impacts of air pollution. Aware of this growing challenge, Togo’s National Agency for Environmental Management, in partnership with UNEP, is starting an air quality monitoring program, which is expected to put in place a network of monitoring stations for PM2.5 and other pollutants in Lomé (ANGE, 2018).
Adding up the damages to assets, economic production and mortality, the total cost of floods in coastal districts is estimated between US$10 million in Togo to US$1.2 billion in Côte d’Ivoire
Water: The degradation of water resources on coastal zones is often due to human activities—e.g. poor water and sanitation service provision, mining, tourism, agriculture— and natural factors—e.g. sea level rise leading to salt water intrusion in groundwater. This degradation affects both water quality and quantity, with impacts on people’s health and the services provided by ecosystems. The total cost due to water degradation is estimated between US$36 million in Togo and US$485 million in Côte d’Ivoire (Table 3.2.3). When aggregated across countries, the cost of water degradation along the coastal areas amounts to US$949 million, which is equivalent to 1.3% percent of the four countries GDP in 2017.
Pollution from air, water and waste mismanagement imposes an important toll on people’s health and quality of life. It can reach as high as US$0.7 billion, in Côte d’Ivoire
Waste: Waste management is a complex challenge, as it relates to a wide range of wastes, which require distinct ways of handling: municipal, medical, industrial, transport, agricultural, construction, demolition waste, etc. Inappropriate management of these wastes can result in serious consequences. In coastal and marine areas, it can cause problems such as deterioration of marine water quality, reduced tourism opportunities, fish contamination, groundwater pollution, and sometimes human deaths. Insufficient collection of municipal waste on West African coastal areas is a major challenge, leading to bad odors, pollution of environment (e.g. water) and potential health problems. In the four countries, lack of municipal waste collection affects 36-60 percent of urban coastal population and 55–85 percent of the rural one.
When aggregated across countries, the cost of water degradation along the coastal areas amounts to US$949 million, which is equivalent to 1.3% percent of the four countries GDP in 2017
Inappropriate disposal of municipal waste can result in many negative externalities, such as groundwater pollution, air pollution and depreciation of the value of land and houses surrounding the unsanitary landfills. The total cost due to waste mismanagement is estimated between US$20 million in Benin and US$90 million in Senegal (Table 3.3.3). Overall, the insufficient collection and inappropriate disposal of municipal waste generates an economic cost estimated at about US$192 million, or 0.3 percent of the four countries’ GDP.In absolute terms, the greatest cost accrues to Senegal, particularly due to the high proportion of population not receiving municipal waste collection (60 percent in urban and 72 percent in rural areas) and to the impacts of the unsanitary landfill close to Dakar. Côte d’Ivoire also contributes significantly to this cost mainly because of a large population exposed to low collection coverage.
Les Wathinotes sont soit des résumés de publications sélectionnées par WATHI, conformes aux résumés originaux, soit des versions modifiées des résumés originaux, soit des extraits choisis par WATHI compte tenu de leur pertinence par rapport au thème du Débat. Lorsque les publications et leurs résumés ne sont disponibles qu’en français ou en anglais, WATHI se charge de la traduction des extraits choisis dans l’autre langue. Toutes les Wathinotes renvoient aux publications originales et intégrales qui ne sont pas hébergées par le site de WATHI, et sont destinées à promouvoir la lecture de ces documents, fruit du travail de recherche d’universitaires et d’experts.
The Wathinotes are either original abstracts of publications selected by WATHI, modified original summaries or publication quotes selected for their relevance for the theme of the Debate. When publications and abstracts are only available either in French or in English, the translation is done by WATHI. All the Wathinotes link to the original and integral publications that are not hosted on the WATHI website. WATHI participates to the promotion of these documents that have been written by university professors and experts.