Africa's great green wall

Can you stop the desert from growing by planting a great green wall of trees and plants from Dakar in the west to Djibouti in the east?

Eleven countries like Senegal and Mali and Chad say they can and they have already started doing it to stop their land and crops from disappearing into a pile of Sahara desert sand.

Now they are meeting in Chad to further their plans.

To find out more about the great green wall, BBC Network Africa's Audrey Brown spoke to Jean Marc Sinamassi, the regional programme manager for the Global Environment Facility, one of the organisations behind the idea.