Africa’s ‘Great Green Wall’ could have far-reaching climate effects

A massive line of vegetation in the Sahel may intensify the West African monsoon, simulations show

photo of the Sahel landscape in Mali

The southern edge of the Sahara is bordered by a semiarid zone called the Sahel (shown here in Mali). The “Great Green Wall” project aims to stop desertification by planting a massive line of trees in the Sahel. Those trees, new research shows, could also have a powerful effect on the region’s climate.

Timothy Allen/Stone/Getty Images Plus

Africa’s “Great Green Wall” initiative is a proposed 8,000-kilometer line of trees meant to hold back the Sahara from expanding southward.