A new study has systematically assessed the ecological impact of China's Three-North Protective Forest Program—the world’s largest afforestation initiative—over the past 45 years. Led by researchers from the Institute of Applied Ecology (IAE), Chinese Academy of Sciences, the study highlights significant achievements while also identifying challenges that need to be addressed in future phases.

The findings, published in SCIENCE CHINA: Life Sciences, reveal that between 1978 and 2022, forest coverage in the Three-North region increased by 92%, and overall forest quality improved by 21%. The program, designed to combat desertification, soil erosion, and agricultural instability in arid and semi-arid regions of northern China, has also contributed to a 4–10% rise in crop yields through shelterbelt establishment, while sand-fixing vegetation has played a crucial role in preventing desertification, and the total area of soil erosion due to hydraulic forces was reduced by 61%. The study by IAE researchers estimates that the program has sequestered 1.96 petagrams of carbon (Pg C), equivalent to 5% of China's industrial CO₂ emissions over the same period.

Despite these gains, researchers have highlighted several ongoing challenges. Only 10% of farmland is effectively protected by shelterbelts, and the effectiveness of sand-fixing forests in controlling desertification is lower than expected. Additionally, a significant proportion of shelterbelt forests are experiencing dieback. Water storage in the region has shown a decreasing trend, with afforestation efforts merely accounting for approximately 8% of this decline. The study emphasizes the need for future afforestation strategies to be based on regional water resource capacity, balancing ecological, agricultural, and residential water demands.

The Three-North Protective Forest Program, launched in 1978, is planned to span 73 years (1978–2050) and is divided into three phases with eight construction periods. With the current phase (2021–2030) underway, the study provides critical scientific insights to guide the program’s continued success and adaptation to environmental constraints.