The African Great Green Wall initiative has reopened discussions on this concept, its significance with respect to combating desertification, as well as its effectiveness and cost

Based on fragmentary knowledge culled from sometimes very early experience, the scientific community, civil society organization and the media have focused on the situation and issued public criticisms and questions. In 2011, CSFD members have written a first synthesis of science knowledge on this project in order to attempt to answer some of the questions. This fact sheet summarizes the key points.
The pan-African Great Green Wall (GGW) is an initiative that was meant in 2007, the year of its launch, to involve the planting of a 15 km wide transcontinental forest belt running from Dakar to Djibouti. This major project was designed to combat desertification. The band of vegetation is to be as continuous as possible, but it may be rerouted if necessary to skirt around obstacles (streams, rocky areas, mountains) or to link inhabited areas (see www.grandemurailleverte.org)

Scientists have and are still being queried by people, NGOs and donors on the merits and feasibility of this project. In 2011, members of CSFD drew up a summary of scientific findings to help answer these questions.

This review can be downloaded at: www.csf-desertification.org/great-green-wall
This fact sheet summarizes the key points.

Three misconceptions should be clarified before being able to shed light on the issue and provide useful advice.
Misconception n°1: The desert is a disease
The Sahara is sometimes considered as a kind of disease that spreads into surrounding areas. However, this desert is actually a healthy and precious ecosystem that, like other deserts worldwide, contributes to the Earth’s diversity and wealth. It is not in any way the image of an unhealthy environment. Global warming has modified its extension pattern in the past, and current climatic changes could lead to a gradual shift in some of the desert boundaries.

Misconception n°2: The Sahel is being invaded by a sand sea
Some people think that a gradually advancing sea of Saharan sand dunes is relentlessly invading the Sahel, but this is not the pattern that scientists have noted. Sand has been shifting in some areas, but these are local manageable phenomena and, moreover, the sand does not always move in a southward direction. Hence, this is not a continent-wide movement trend that should be halted like an invader.

Misconception n°3: A great forest wall could be planted in uninhabited or sparsely inhabited regions
On the contrary, the proposed trajectory is to pass through inhabited regions where agriculture and livestock farming are already fully developed on lands allocated according to local traditions. Local inhabitants should thus be associated with any initiatives designed to combat desertification via tree planting.

Recommandations for decisionmakers
The following recommendations are based on the analysis of agrosilvopastoral management results:

Adopt a flexible approach in order to make effective use of the best sustainable land management practices,,while taking the results of many completed green belt, plantation and agroforestry projects, and local know-how, into account.
Identify and boost farmers’ awareness on the most effective regeneration techniques, that are easy to manage (technically and financially) and cost-effective.
Rely on the decentralization process by ensuring the participation of inhabitants in planting the GGW and highlighting the potential benefits for them (improved land fertility, yields and the diversification of income-generating activities):
promote very simple local structures such as rural markets, etc.
reinforce management training for members of local structures, including women
set up a suitable institutional framework for fiscal and land planning, while ensuring decentralization in order to strengthen local resource management, planning and development control capacities.
Foster ecological intensification of agriculture and livestock farming,so as to reduce pressure on forest resources.

All of these recommendations are geared towards the integration of greening strategies in a regional sustainable management framework in order to deal with the geopolitical issues that this region faces.