African nations are planting a continent-crossing Great Green Wall made entirely of vegetation and providing food security for millions.

When it is finished, the Great Green Wall will cross the width of Africa, and be roughly three times the size of the Great Barrier Reef. Designed as an all-natural, multi-purpose vegetative blockade against damaging desert winds and sand, it is hoped to become the region of Sahel’s lifeline back to a source of food and employment for the country. Although the concept of a green wall for Africa was first proposed by British environmental scientist Richard St. Barbe Baker back in 1952, it wasn’t until 2007 that a plan was formally announced with the backing of the African Union. The Sahel region is a vital link for millions of Africans who rely on it for crops, but because of decades of severe drought and soil erosion 40% of the land there is currently unusable. Thousands of miles of trees and crops are an extreme response to an extreme situation, but the backers of the Great Green Wall think it will be a unifying force of nature the entire country will work together for.