Planting trees by the billions in order to generate moisture, fight desertification, and combat the effects of climate change: it’s a huge challenge with a historic precedent.
What started in China…
In 1978, China embarked on a massive undertaking to fight the advance of the Gobi Desert. Dubbed the “Great Green Wall,” the project currently consists of 32 million newly forested acres, and aims to hit 1 billion planted trees by 2050. The project extends over some 2800 miles across north and northwest China, and although there is still net tree cover loss in the country, the annual amount has been decreasing, in part because of the Great Green Wall. According to a study published in the academic journal Nature Climate Change, China’s reforestation efforts have helped to offset 81% of the losses in tropical deforestation since 2003.
…is moving to Africa
Faced with the advance of the Sahara Desert into the Sahel region as a result of climate change, Africa is taking inspiration from this project to construct its own Green Wall. The region’s population has been subject to a drought for over thirty years, along with advancing desertification. According to a report from the UN’s Food and Agriculture Organization, the 11 countries (collectively home to over 230 million people) that lie in the Sahel region are losing 1.7 million hectares of forest annually*.
When an area becomes more arid (in the Sahel region, a result of rising temperatures), surface vegetation dies, exposing the soil to wind and causing it to lose its nutrients, which leads to soil death and accelerating ecological collapse. The ecological damage caused by climate change and human activity has meant that the Sahara desert is expanding into the Sahel, which has led to more frequent dust storms and the loss of both tree cover and agricultural land that local communities depend on.
Originally launched in 2007, Africa’s Green Wall will stretch from Senegal to Djibouti—7000 kilometers long, and 15 kilometers wide. Thus far, more than $8 billion has been pledged towards the completion of the wall. The project aims to restore 100 million hectares of land by 2030, sequestering 250 million tons of CO2 and creating 350,000 jobs along the way.
Long term evolution
However, the actual implementation of the Green Wall has evolved since it was first launched in 2007. Early on, researchers pointed out that tree-planting initiatives in the Sahara had stretched back decades, often with little success. "If all the trees that had been planted in the Sahara since the early 1980s had survived, it would look like Amazonia,” Chris Reij, a specialist in land management and senior fellow at the World Resources Institute, told the Smithsonian Museum’s online magazine.
Instead of planting a line of trees on the southern edge of the Sahara, the project has become more comprehensive, taking into account local ecosystems and incentives for local farmers to protect and promote tree growth on their lands. The new vision for the project involves surrounding the Sahara with “a wide belt of vegetation,” that protects an agricultural landscape—both in North Africa as well as the Sahel.
By scaling up efforts to shift local agricultural practices, as well as changing the incentives and perceptions that affect how farmers manage trees on their land, the African Union, World Bank, UN, and major NGO partners hope that re-greening the Sahel can be achieved within the next 15 to 20 years.