The Great Green Wall is one of the most ambitious environmental projects ever conceived, creating a vast belt of vegetation spanning Africa by 2030; from Senegal on the Atlantic to Djibouti on the Red Sea. It was heralded as Africa’s contribution to the fight against climate change, reversing damage caused by drought, overgrazing and poor farming techniques. The regreening of 11 Sahel countries on the edge of the Sahara Desert would create millions of jobs, boost food security, and reduce conflict and migration. The plan was launched by the African Union in 2007, and despite political consensus, only 4% of the Great Green Wall had been completed by 2021. So what has gone wrong? What lessons have been learned, and will a change of strategy ensure its success by the end of the decade? Presenter: Audrey Brown Producer: Ravi Naik Editor: Tara McDermott Researcher: Anoushka Mutanda-Dougherty Broadcast Co-ordinators: Brenda Brown (Photo: The Niger river in Mali. Credit: Getty images)