Africa’s proposed 4,000-mile wall of trees stretching from Senegal to Djibouti is designed to stop encroaching desertification
Senegal’s capitol city Dakar sticks out into the Atlantic Ocean on a peninsula. It’s at least a thousand miles to the Sahara desert yet the air today is so thick with sand that the tops of buildings disappear in a sandy haze.
It’s the worst sand storm in a year and people here are worried that climate change will cause these events to be more common. Seasons are shifting across the region. In Senegal the rainy season used to start in July or August but now it doesn’t start until September. Decreased rain – along with over grazing of land – is causing an increase in deserts across the Sahel. Roughly 40 per cent of Africa is now affected by desertification and according to the UN, two-thirds of Africa’s arable land could be lost by 2025 if this trend continues.
Senegal is one of 11 countries in the Sahel region of Africa looking towards the same solution to the desertification problem: The Great Green Wall. The goal of the project is to plant a wall of trees, 4,300 miles long and 9 miles wide, across the African continent, from Senegal to Djibouti. African leaders hope the trees will trap the sands of the Sahara and halt the advance of the desert.
Papa Sarr is Technical Director for the Great Green Wall in Senegal: “We are convinced that once we start to plant the wall of trees dust will decrease in Dakar,” he says.
Sarr sits in the passenger seat of a four-wheel drive on his way to Widou, a village he hopes will serve as a model for the Great Green Wall in Senegal. The paved roads of Dakar give way to red sand paths of the Sahel; a dry savanna transition zone between the equatorial jungles in the south and the Sahara to the north. Black and white goats meander in front of the truck and flat-topped acacia trees dot the sandy landscape. They are virtually the only vegetation in a region where the dry season can last up to 10 months.
Four hours northwest of Dakar, the village of Widou sits next to one section of Senegal’s Great Green Wall. The acacia trees here are just four years old, waist high and thorny. The trees are surrounded by a firewall and a metal fence to keep out tree-eating goats. All of the trees were chosen carefully. Sarr says, “When we design a parcel we look at the local trees and see what can best grow there, we try to copy Nature.”
Two million trees are planted in Senegal each year; but all of them must be planted during the short rainy season. Labourers plant acacia saplings in the sand along with animal manure for fertiliser. Sarr points to a three feet tall tree. “This one is Acacia nilotica. It produces Arabic gum used in local medicine and a fruit that can be eaten by animals.”
For the project to succeed, it was crucial to plant trees that would also provide benefits for people living here. The government has ambitious plans for planting more trees but the Great Green Wall is also a development project, aimed at helping rural people.