The Great Green Wall, officially known as the Three-North Shelter Forest Program (simplified Chinese: 三北防护林; traditional Chinese: 三北防護林; pinyin: Sānběi Fánghùlín), is a series of human-planted windbreaking forest strips (shelterbelts) in China, designed to hold back the expansion of the Gobi Desert and provide timber to the local population. The program started in 1978 and is planned to complete around 2050, at which point it will be expected to have created a vast green barrier spanning approximately 4,828 kilometres (3,000 mi) long and up to 1,448 kilometres (900 mi) wide in certain regions, and will encompass around 88 million acres of forests.

The project's name indicates that it is to be carried out in all three northern regions: the North, the Northeast, and the Northwest. This project has historical precedents dating back to before the Common Era. However, in premodern periods, government-sponsored afforestation projects along the historical frontier regions were mostly for military fortification.

China has the largest desert area of any country and is heavily affected by sandstorms. However, the country has implemented various measures to restore grasslands and forests, successfully slowing and now reversing overall desertification. In November 2024, China's government reported the completion of the 3,000 km green belt around the Taklamakan Desert. The fraction of the country covered by deserts declined from 27.2% in the previous decade to 26.8%.

Initiated mostly in Northern China, the Great Green Wall of China is a massive reforestation project meant to counteract desertification and slow down the consequences of climate change. Starting in the 1970s in reaction to the Gobi Desert incursion, the project was driven by the Chinese government. Early projects included massive tree planting to stop desertification and safeguard local communities and agricultural territory. Aiming to build a green barrier against desertification, dust storms, and ecological damage, the government started the "Three-North Shelterbelt Program" in the 2000s. This effort developed over time into the enormous environmental rehabilitation project known today as the Great Green Wall.

Desertification, which involves either human or natural activity changing normal humid areas to dry desert conditions, is a large and increasing problem faced by modern China. 29.7% of China had been desertified by the year 2000, with the rate of change increasing almost every year. In 2003, Worldchanging reported that 3,600 km² (1,400 sq mi) of Chinese grassland were being overtaken annually by the Gobi Desert. In June 2001, National Geographic reported that annually, the dust storms blow off as much as 2,000 km² (800 sq mi) of topsoil, and the storms increase in severity. Such storms have serious agricultural impacts on other nearby countries, including Japan, North Korea, and South Korea. The main cause of these changes was human activity, with water usage, mining, excess farming, and wood cutting being the top contributors. In 2022, Time reported progress in desert stabilization and that thousands of acres of shifting dunes had been stabilized, while the nationwide frequency of sandstorms, including those affecting Beijing, had "especially" dropped by one-fifth between 2009 and 2014.

In 2017, National Geographic reported that the policies in place at the time had contributed to the reduction of China's forests and grasslands. One example was the 'grain first' policy, which required grasslands to be converted into croplands. Reducing grass coverage eliminated one of the barriers to desertification. Most of these causes can be attributed to an underlying issue: population growth. The number of people living in important ecological areas has grown beyond the carrying capacity of those areas. In 2019, a study published in Nature Sustainability, found that while human activity had previously been associated with land degradation, these policies had led to a net increase in vegetated land in China.

In the past 40 years,^[when?] the world as a whole has lost a third of its arable land due to desertification. Increasing desertification and related storms have caused some major issues for people living in China, especially around the Gobi desert. Crops and buildings are being damaged or destroyed. This has forced many people, who are now called "climate refugees" to leave their homelands. In total, the effects of desertification have affected the lives of over 400 million people. The Green Wall project was started in 1978, with the proposed result of raising northern China's forest cover from 5 to 15 percent, thereby reducing desertification.

Yin Yuzhen planted trees to rehabilitate the desolate environment in the Uxin Banner of China's semi-arid western landscape. Yin's afforestation efforts have been recognized by individuals such as Chinese Communist Party general secretary Xi Jinping, who, during the 2020 National People's Congress, described the actions of those such as Yin as a remarkable achievement and an overall improvement of the ecology in China.