Africa's 'Great Green Wall' is a massive 8000-kilometre planting project aimed at holding back the spread of the Sahara Desert.
Like a green line across the continent from Senegal in the west to Djibouti in the east, it's both planting trees and restoring degraded land to boost food production.
Andrew Millison has recently visited the wall.
He is one of the world's foremost experts on permaculture, where landscaping and horticulture replicates natural systems.
He is the founder of the Oregon State University Permaculture Program and travels the world turning his passion into popular explainer videos on his YouTube channel.
Photo: Supplied by Andrew Millison
