For more than four decades, China has been working to halt the spread of desertification through the Three-North Shelterbelt programme, colloquially known as the Great Green Wall. INNER MONGOLIA: At first glance, the Engebei Ecological Demonstration Zone looks out of place. Banana trees, papayas and dragon fruit thrive under the winter sun inside greenhouses on the edge of the Kubuqi Desert in northern China’s Inner Mongolia. Just decades ago, this land was dominated by shifting sand dunes.