The Great Green Wall
Africa is desertifying. The expansion of the Sahara Desert into the Sahel, the region between the Sahara and the Sudanian savanna, is making vital farmland and resources in the Sahel disappear. According to the Journal of Climate in 2018, the Sahara Desert has expanded significantly over the 20th Century, by 11%-18% depending on the season, and by 10% when defined using annual rainfall. The desert is mostly expanding to the Sahel in the south, which is detrimental to the lives of the 135 million people that live in the Sahel. The population of the Sahel is expected to grow to around 340 million by 2050, putting even more people in danger. The desertification of the Sahara is already causing food and water shortages, and this is only expected to worsen. One of the most important resources in the region, Lake Chad, has shrunk to less than 10% of its size at full capacity. 30 million people are at risk of losing their entire water supply. Military conflicts are also becoming more frequent because of these shortages, only worsening the problem. Desertification is getting so bad around the world that the United Nations created a special convention to address this, the Convention to Combat Desertification (UNCCD).
In 2007, under the leadership of the African Union, plans were unveiled for a potential solution to this problem, known as the Great Green Wall. The plan is to plant a wall of trees from Senegal to Djibouti, to stop the expansion of the desert. When completed, it will be around 4,800 miles long and 10 miles wide. This is roughly three times as long as the Great Barrier Reef in Australia. The estimated cost of constructing this is around 8 billion dollars. That sounds like a lot, but it is a small price to pay compared to the damages an expanding Sahara could cause. This project is being spearheaded by the African Union, but it is being helped by the United Nations as well as many individual countries.
There are many benefits of the Great Green Wall other than desertification. The new trees could pull a tremendous amount of carbon dioxide out of the atmosphere. The amount of carbon dioxide taken from the atmosphere would be equivalent to all of the cars in California being taken off the roads for three and a half years. Also, if done correctly, these trees could drastically increase biodiversity in the region, making surrounding ecosystems healthier and helping to combat climate change.
This is not the first time something like this has been attempted. In 1978, China rolled out the plan for the Great Green Wall of China, which had the goal of stopping the expansion of the Gobi Desert. This project is expected to continue until 2050, and it aims to plant around 88 million acres of forests in a wall about 3,000 miles long and as much as 900 miles wide in some places. While this project is working, and many parts of the Gobi Desert have stopped expanding, there are many problems. Firstly, many of the trees planted were not cared for, so they died, meaning less carbon dioxide is being sucked from the atmosphere. Also, many areas just have rows of trees and no biodiversity. This is bad because the lack of biodiversity means that an ecosystem cannot thrive, and so the forest does not regenerate very well. If this problem is not fixed, humans will have to plant new trees every generation, so costs will skyrocket. India is also planning a wall of trees to stop the eastward march of the Thar desert, but this idea is still in its infancy.
We are over a decade in and the Great Green Wall is roughly 15% complete, with the most significant gains in Senegal (11 million trees planted), Nigeria (5 million trees planted), and Ethiopia (15 million trees planted). So far, it is working pretty well, though there are some huge flaws. For example, trees cannot just be planted. They have to be taken care of for years. Much of the wall is in remote areas, so it is hard to get people to these areas to take care of the trees. Also, this project requires an incredible amount of manpower, a lot of which does not exist. But the stakes could not be higher, and as of now, this dream is still likely to become a reality.
While the Great Green Wall is a fantastic idea, it alone will not stop climate change. We have to do much more, from curbing fossil fuels to preserving more of nature, to truly end this disaster. We must take action now before it is too late.
Learn more at greatgreenwall.org
Also, this is not a picture of the Great Greet Wall. I’m using a picture I took so I don’t have to deal with Copyright laws.