The Great Green Wall of the Sahel: profitably turning a desert into an orchard
The Sahel stretches south of the Sahara, from Senegal in the west to Ethiopia in East Africa. Today, due to droughts, poor agricultural cultivation methods and excessive use of land due to increasing demand for food or firewood, vast areas of what was once a fertile and productive region are practically uncultivated.
To try to reverse this situation, as well as the continuous advance of desertification throughout the area, in 2007 an initiative led by the African union He planted the idea of planting a line of trees that, some 8,000 kilometers long and 15 wide, would cross the driest areas of the Sahel. The project would be known by the name of the Great Green Wall of the Sahel, and the barrier, with which it was intended to stop the advance of the desert, would extend from Senegal in the West, to Eritrea, at the opposite end of the continent, crossing a total of 11 countries and restoring approximately 100 million hectares of land.
However, so far, this ambitious goal is a long way from being achieved, in part due to a lack of financial resources. Now, however, this could change in the near future, or so the most optimistic believe due to the promise of several countries in the framework of the summit One Planet Summit for Biodiversity, held on January 11 of this year, to donate 13,000 million euros to carry out the titanic project. “But to use these funds efficiently, we now have to ask ourselves where and for what measures should they be used more sensibly. “emphasizes the doctor Alisher Mirzabaev of the Development Research Center -ZEF- of the University of Bonn.
20 cents for every euro invested of net profitability
Mirzabaev, an agricultural economist, is the director of a study entitledEconomic efficiency and targeting of the African Great Green Wall, was recently published in the magazine Nature, and in which, the researchers they divided the Sahel region into 40 million 25-hectare parcels.
Once the territory is dissected, Mirzabaev’s team analyzed which land restoration measures would be ideal for each of the plots and how much it would cost to carry them out. They then stipulated the economic benefits that could be achieved. “On the one hand, we include the so-called provisioning services,” explains the economist. “This includes the things that ecosystems produce: food and drinking water, raw materials such as wood or medicinal plants.” “We also took into account other effects of the initiative, such as improving the local climate, reducing wind erosion. or the services provided by pollinators, which in turn increase the yield of farmers’ crops, “he adds.” The results show that the construction of the “Green Wall” would also be worth it economically, “he continues, pointing out, however. , the great dependence on various factors that these measures would have.
A pulse to the desert
As the researchers explain, as a general rule, reforestation would be the most economically and ecologically advantageous solution. This has the disadvantage that it takes decades for a few hundred seedlings to become a forest, therefore we would talk about an investment only capable of paying off in the very long term.
Nevertheless, the situation becomes different when degraded areas are turned into farmland. “Ideally, the first harvest is possible after just one year,” says Mirzabaev. Thus, farmland restoration can pay for itself comparatively quickly. Furthermore, many poor small farmers also prefer quick returns from their restoration activities. However, the gains that can be achieved as a result are significantly less, as are the environmental effects.
“In our analysis we work with different scenarios, some of which point to more short-term benefits, while others will generate more long-term returns,” explains the agricultural economist, who is a member of the Transdisciplinary Research Area “Sustainable Futures” of the University of Bonn. For example, the so-called baseline scenario, the most affordable contemplated by scientists, includes a combination of both short-term and long-term returns in which each euro spent produces an average net return of 20 cents.
The African curse
Among the regions that could benefit the most from the consolidation of the Green Wall are Nigeria, Eritrea and Ethiopia. “This is where the investment in the Green Wall would pay off,” says Mirzabaev. To finance all the measures proposed in this scenario, a sum of 44,000 million euros would be needed, which would allow the restoration of 28 million hectares of land.
However, despite the optimism of those most confident with the initiative, in a territory that crosses the African continent from east to west in the area of its maximum latitudinal extension, there are enormous regional variations, and half of the profitable regions contemplated are too much insecure to act.
This is why the analysis also shows that this will probably only work in theory. The reason is that, Due to conflict, tribal disputes and wars, many of the regions where it would make sense to build the Great Green Wall are simply too unsafe to adopt such measures. “If we remove these areas, we are left with only 14 million hectares,” says Mirzabaev. “This shows how such disputes not only cause direct human suffering, but also prevent the positive development of the affected regions,” he concludes with a bittersweet taste in his mouth. And it is that Green Wall of the Sahara, could become one of the greatest works of agroforestry engineering ever carried out by human beings, but to win a pulse against nature and the desert, man seems to first have to settle accounts with himself .