GoKawiilAbout 40% of the world’s land surface is classed as drylands1 — deserts and water-scarce grasslands, shrublands and savannahs. Life can be tough for the more than two billion people that live there. In Chinguetti, Mauritania, Saharan dunes push into streets and courtyards, burying homes and forcing residents to move to other towns. In Mongolia, a lack of rainfall is placing immense pressure on herders and ecosystems, and sending dust and sandstorms across the border into China and South Korea2.
What China’s Great Green Wall can teach the world
Arid regions are spreading, owing to global warming. By 2100, half of Earth’s land area is expected to be dryland3, with five billion inhabitants1. And human activities such as agriculture are exacerbating problems by removing protective vegetation, compacting and degrading soil and reducing the land’s capacity to retain water.
To meet this challenge, many countries have set up large programmes to combat desertification. One of the largest is China’s Three-North Shelterbelt programme, also known as the Great Green Wall of China. Begun in 1978 and scheduled to run until 2050, the project involves creating a huge patchwork of forests and planted areas across northern China, spanning 40% of the country, to stabilize the movement of sand4 (see ‘A country-wide endeavour’). The intent is to shield farms, villages, roads and railways from the encroaching Gobi and Taklamakan deserts.
Forest cover in the region has nearly tripled, from about 5% in 1978 to just under 14% in 2023. The area affected by soil erosion has declined by two-thirds. The intensity and frequency of dust storms have fallen5, improving air quality in downwind cities such as Beijing.
It’s not always easy. In the driest zones, trees continually die and the area needs replanting. In some places, planting of a single species has left forests vulnerable to disease. In 2024, about 27% of China’s territory was still classed as desert — a decline of only 1.5% since 2014.
Beyond China, green-wall projects across Africa, India and the Gulf states have struggled to reap benefits. For example, Africa’s Great Green Wall, a continent-spanning reforestation initiative led by the African Union, managed to restore only four million hectares of degraded land6 between 2007 and 2020 — putting it way off its target of rehabilitating 100 million hectares by 2030.
Over the past few decades, we have tracked desertification and efforts to combat it across China, Africa and beyond. In our view, countries across the world could benefit from adopting aspects of China’s strategy to keep more of the desert at bay.
Why green walls fail
Most green-wall projects start with a simple vision: plant more trees to contain drifting sand. Yet, early greening is hard to sustain, because young trees succumb easily to drought, grazing and neglect7.
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