The Sahel region of Africa faces one of the world’s most severe challenges from climate change and land degradation. Persistent drought, soil erosion, and the resulting loss of arable land threaten the livelihoods of millions across the continent. This process of desertification is compounded by a rapidly growing population, which places unsustainable pressure on already fragile ecosystems. In response to this escalating crisis, the African Union launched the ambitious Great Green Wall (GGW) initiative in 2007. This effort is a large-scale attempt to reverse environmental decay and build climate resilience across a vast area. The goal of the project is to restore 100 million hectares of degraded land by 2030, transforming the future of the region.
Defining the Great Green Wall’s Scope
The Great Green Wall is not a literal, continuous barrier of trees, as the initial concept might have suggested. Instead, the project has evolved into a comprehensive, integrated ecosystem management program, focusing on a mosaic of land-based interventions. The initiative spans the entire breadth of the African continent, stretching approximately 8,000 kilometers from Senegal in the west to Djibouti in the east, across the semi-arid Sahel belt. This area encompasses 11 core countries that are actively implementing the project.
The project’s mission shifted significantly from its initial vision of a simple 15-kilometer-wide tree line to a broader strategy for rural development and ecological rejuvenation. The focus is now on promoting sustainable land and water management practices tailored to local conditions. This refined approach recognizes that restoring the landscape requires a combination of climate-smart agriculture, sustainable pastoralism, and conservation forestry. The shift ensures that the interventions are ecologically sound and economically beneficial for the communities who depend on the land.
Holistic Land Management Techniques
The land restoration work relies heavily on reviving and adapting indigenous farming methods to capture and conserve scarce water resources. One effective water harvesting technique involves the use of zai pits, which are small planting holes dug into the soil to trap rainwater and organic matter. These pits are often enriched with compost or manure, providing a fertile micro-environment that can help boost local crop yields by up to 50%.
Another technique is the construction of demi-lunes, or crescent-shaped earth mounds that follow the contours of the land to slow water runoff and increase infiltration. These structures, along with terraces and trenches, maximize the absorption of rainfall, preventing soil erosion and recharging local groundwater tables. The project also promotes Farmer-Managed Natural Regeneration (FMNR), which involves protecting and nurturing the stumps of native trees and shrubs to allow them to regrow. This practice creates a canopy that protects the soil and incorporates trees into the agricultural system, a form of agroforestry.
The selection of plant species focuses on native, drought-resistant varieties that also provide economic utility to local populations. Species like the desert date, baobab, shea, and various acacias are chosen because they can thrive in the harsh Sahelian climate while also providing:
- Food
- Fodder
- Medicine
- Income
This combination of water conservation, soil enrichment, and strategic planting ensures the long-term viability of the restored landscapes.
Ecological Restoration Outcomes
The large-scale application of these land management techniques is producing measurable environmental improvements across the Sahel. Satellite-based monitoring shows a positive trend in the Normalized Difference Vegetation Index (NDVI) in many project areas, indicating an increase in photosynthetic activity and overall plant health. This greening signifies a reversal of land degradation, with evidence suggesting that the encroachment of the Sahara desert is retreating in certain regions.
The restoration efforts contribute to improved soil health by increasing the soil’s organic matter and moisture-holding capacity. Vegetation cover, established through techniques like FMNR and agroforestry, helps to reduce the speed of surface water flow, allowing more water to infiltrate the ground. This enhanced water retention is fundamental to building climate resilience in a region characterized by highly variable rainfall. The project is also a contributor to global efforts to combat desertification, with approximately 30 million hectares of degraded land reported as restored across the participating countries as of 2024. The GGW is helping to conserve local biodiversity by creating new habitats and protecting existing ones.
Socio-economic Transformation
The success of the Great Green Wall is measured not only in restored hectares but also in the transformation of human livelihoods. The initiative has a goal of creating 10 million green jobs by 2030, offering economic opportunity in a region with high rates of poverty and youth unemployment. These jobs are directly related to restoration activities, such as establishing nurseries, planting and monitoring trees, and processing non-timber forest products. The project has already resulted in the creation of hundreds of thousands of jobs, fostering a network of local entrepreneurs.
Improved soil quality and water availability have led to significant gains in agricultural output, enhancing food security for local communities. Farmers are experiencing more reliable harvests, which lessens their reliance on external aid and provides a surplus for local markets. The increased productivity also contributes to a greater sense of stability, providing a “reason to stay” for populations who might otherwise be forced to migrate due to resource scarcity.
The project places a strong emphasis on community empowerment, particularly for women and youth, who are often at the forefront of the restoration work. By supporting women-led initiatives and training local people in sustainable land management, the Great Green Wall is building social cohesion and ensuring that the restoration efforts are sustained by the people who know the land best.