After 17 years, the “Green Great Wall” project has restored over 7.7 million hectares of land across Africa.
Over the past few decades, deforestation, agricultural expansion, and drought have all contributed to desertification in many areas across the African continent. Fertile soil has turned barren, leading to decreased productivity. More than a dozen African countries are battling desertification with an ambitious project aimed at planting trees and crops on 100 million hectares of land, an area 2.3 times the size of California. The goal of the 17-year-old Great Green Wall (GGW) project, estimated to cost between $36 and $49 billion, also includes creating 10 million jobs and reducing 250 million tons of carbon by 2030, according to Business Insider.
Trees planted in Walalde, Senegal. (Photo: Reuters).
Countries from Senegal to Djibouti are trying to re-green the semi-arid Sahel region, a strip of land stretching from the Atlantic Ocean to the Red Sea. The West African forests once covered over 129,500 km2. Since 1975, deforestation, primarily for agricultural expansion, has reduced forest area to about 82,880 km2, according to the U.S. Geological Survey. Besides rendering the land less fertile, desertification makes the soil more vulnerable to wind erosion and decreases its moisture retention capacity. It also leads to a loss of biodiversity in flora and fauna. All these factors make it increasingly difficult for people to survive.
The African Union officially launched the project in 2007. Initially, the GGW included 11 countries: Burkina Faso, Chad, Djibouti, Eritrea, Ethiopia, Mali, Mauritania, Niger, Nigeria, Senegal, and Sudan. In the years following its inception, many other countries joined. At first, the project aimed to fill an area of 16 x 7,000 km of the Sahel with trees. Trees can help slow soil erosion, absorb carbon dioxide, and promote biodiversity by providing food and shelter for wildlife.
However, critics point out numerous shortcomings, and the project has faced several barriers. A major issue in the tree-planting plan is the trees themselves. Some saplings are poorly developed or die. They are planted in remote areas, making care difficult. Rising temperatures and low rainfall have also contributed to the problem. Some communities argue that the government has not adequately mobilized local indigenous people for the project. The governments of many other countries intentionally relocated many people from homes located in forested areas and conservation zones.
The success of the GGW has also been difficult to track in some areas. Independent experts have struggled to verify some government data. By 2020, the project had only completed 4%. In 2021, world leaders committed to investing $19 billion to support measuring and promoting the success of the project.
At that time, the focus of the GGW began to shift towards integrating traditional planting and irrigation methods. Before the GGW began, local people in many areas of Niger and Burkina Faso started using a technique called farmer-managed natural regeneration. Instead of planting new trees, farmers in central-southern Niger encouraged the care of existing shrubs and large trees. This activity helped re-green 4.9 million hectares and plant 2 million trees. In Burkina Faso, farmers relied on traditional experience to adapt after droughts in the 1970s and 1980s. They dug deep holes called zai and built stone barriers to help collect and retain moisture.
Since the start of the GGW, many countries have achieved success with small farmer-initiated projects. In Senegal, farmers began planting zai gardens during the Covid-19 lockdown. Known as Tolou Keur in Wolof, the semi-circular pits collect and direct water to crops. While not every Tolou Keur survives, many gardens are thriving. Farmers grow everything from sorghum to hibiscus. The semi-circular pits are built quickly, occupy minimal space, and only require about 10 people to maintain.
Drones and satellites have recently started providing insights into rehabilitated land, using AI to identify individual tree species. Many tech startups and organizations, such as the Food and Agriculture Organization of the United Nations (FAO), are collaborating to help communities in the Sahel map and monitor baobab tree populations, aiding in soil erosion reduction. Ethiopia, Niger, and Senegal have all re-greened parts of their land. In addition to zai gardens, Senegal has planted 20,234 hectares of trees. In 2023, the United Nations Development Programme reported that the GGW project had completed 18%, restoring over 7.7 million hectares of land and creating 350,000 jobs.
