7. Africa's "Great Green Wall"

My last post looked at physical soil restoration in a small Kenyan case study. This post looks at physical soil restoration on a larger continental scale. The Great Green Wall is a pan African tree-planting project that aims to fight desertification in the Sahel.

Fig. 1 Logo of Africa’s Great Green Wall project, which began in 2008

The Sahel:

The Sahel is the semi-arid transition zone between the Sahara desert to the north and the wooded African tropics to the south.

Fig. 2 Map showing the Sahara desert in the north, the transitional semi-arid Sahel zone and then the wooded African tropics in the south

The problem:

In the Sahel, overgrazing, over-cultivation and deforestation (for firewood) are causing soil erosion and anthropogenic climate change is creating drier conditions. The combination of these two factors is leading to desertification and expansion of the Sahara desert.

Fig. 3 Desertification in the Sahel (Source: CNN, 2016)    

The solution:

The Great Green Wall (GGW) project aims to plant a 15km wide and 8,000km long continuous belt of trees across the African continent (within the Sahel region) to try to prevent and reverse desertification. The idea is that the trees with help hold the soil together and retain water.  It began in 2008 and is still ongoing, but if completed it will be the largest living ‘structure’ on Earth. The photo below shows its full anticipated extent…

Fig. 4 The full anticipated extent of the 15km wide and 8,000km long Great Green Wall

The BBC video below gives a good overview of the GGW…