Desert greening is when people plant trees and shrubs in desert areas to make the land healthier. It helps to reduce air pollution, make the land look more nature and also help to protect animals and birds that live in the area. People do this by planting trees and shrubs that will survive in the hot, dry desert climate. These plants need water, so people use wells and other sources of water to help keep the plants alive. In time, the desert area can become a healthier, more vibrant environment.