Improving the economic efficiency and targeting of Africa’s Great Green Wall

Frequent droughts and unsustainable land use are causing extensive land degradation in the Sahel region of Sub-Saharan Africa, reducing ecosystem services provided by land, lowering crop productivity, and increasing food insecurity and poverty.

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To address the devastating impacts of climate change and land degradation, the Great Green Wall (GGW) programme was initiated in 2007 by the African Union with the main objective of restoring 100 million hectares of degraded ecosystems across 11 countries. Due to several factors such as the increasing number of conflicts, lack of funding, and insufficient implementation capacities, the progress of land restoration activities within the Great Green Wall (GGW) initiative has so far been slow. 

Left: Aerial view of the site prepared for land restoration in Burkina Faso under the FAO’s Action against Desertification (AAD) program - Right: Aerial view of the same site 2 years after being planted with grasses and trees in Burkina Faso

Source: FAO’s AAD program 

We explored the opportunities for increasing the efficiency and targeting of GGW land restoration activities in our recently published article, authored by an interdisciplinary team consisting of an economist, a botanist, and geospatial and environmental analysts. 

The idea for this paper was born in 2018 during the Actions Against Desertification (AAD) seminar at the Center for Development Research (ZEF) when Alisher Mirzabaev and Moctar Sacande noted the lack of economic assessments of the GGW project’s impacts, and cost and benefit analysis. After various interactive meetings, in 2019, they agreed to collaborate on this study. As the idea was developing, more people joined this effort. My co-author, Anastasiya Shyrokaya, and I got involved with the project in 2020. My focus in the study was to analyze land use and land cover changes using remotely sensed satellite data, geospatial mapping, and Python and R programming. The biggest challenge in this analysis of land use and land cover trends was to process the high-resolution MODIS product for 18 years, across the entire region. We overcame this by doing the analysis on advanced computers. Anastasiya developed the database on the economic values of ecosystem services and the costs of land restoration actions. For both of us, this was a very exciting opportunity to collaborate with the other colleagues and apply our skills to find solutions for this extremely consequential issue. 

In our paper, we developed nine scenarios capturing various aspects of local decision-making contexts that helped with comparing the costs and benefits of restoring degraded lands and examining the economic returns from land restoration activities across Sahelian countries. We conducted the cost-benefit analysis at a very granular scale, with each analyzed pixel size at 25 hectares. Then, we compiled a Sahel-specific database containing the economic values of ecosystem services from the region. Finally, we estimated the potential challenges that the growing number of violent conflicts in the Sahel can pose on the progress of land restoration activities. 

Our team found that every USD invested into land restoration in the Sahel yielded an average of  1.2 USD under the base scenario, ranging from 1.1 USD to 4.4 USD across the scenarios, and the total amount of investments needed for land restoration would be 44 billion USD under the base scenario. It is particularly remarkable to note that violent conflicts within the region could reduce the accessibility to degraded ecosystems by half,  from 27.9 million hectares to 14.1 million hectares. Our study implies that the land restoration activities in the Sahel need to go beyond agricultural, forestry, or environmental agencies, and the results point to the need for an “all-government” approach, coordinating sectoral policies with respect to land restoration goals. For instance, such land restoration activities should be incorporated into governments’ development agendas and budgets, and be accompanied by measures to improve livelihoods, strengthen tenure rights, and expand access to alternative energy sources.

Our work has also opened a line of new research questions that need further investigation. What are the best approaches for each individual country in the Sahel region to intensify their land restoration activities? To what extent regional conflict resolution strategies can impact the progress of land restoration activities in the Sahel region? How adaptation to climate change will affect the costs and benefits of land restoration in the GGW? We are very much looking forward to exploring these questions in our future work.

For further details, you can read the full paper, "Economic efficiency and targeting of the African Great Green Wall" here.

Farinaz Motlagh

PhD Student, Stony Brook University