Welcome to the MWEB Africa Blog Africa's anti-desert 'green wall' starts small in Senegal The idea was simple, ambitious and eye-catching: to counter the threat of creeping desertification in Africa through a Great Green Wall of trees spanning the continent from Senegal in the west to Djibouti in the Horn of Africa in the east. It would be 7 000km long, and seek to halt or reverse the encroachment of deserts threatening the livelihoods of tens of millions. Some estimates say up to a third of Africa's surface area is at risk. Posted : 2008-10-29