The Sahara Desert is slowly extending its reach across northern Africa. To counter increasing desertification, a group of African nations wants to plant a continuous line of trees across the continent.
The "Great Green Wall" involves constructing a tree belt 15 kilometers (9 miles) wide and 7,775 kilometers (4,831 miles) long across the southern edge of the Sahara, from Senegal in the west to Djibouti, Ethiopia and the Indian Ocean in the east.
Scientists hope the tree belt will counter soil erosion, slow wind speeds, and stop the encroaching desert. It is important that the countries plant drought-resistant native trees that will not further disrupt indigenous environments.
Desertification in tandem with human-induced factors, such as mono-cropping and overgrazing, have substantially degraded agricultural lands across northern Africa. When crops fail, rural towns and villages often follow, as residents flee to urban areas in search of better lives.