Mass tree planting in China is turning one of the world's largest and driest deserts into a carbon sink, meaning it absorbs more carbon from the atmosphere than it emits, new research reveals.
The Taklamakan Desert (also spelled Taklimakan or Takla Makan) is slightly larger than Montana, stretching across about 130,000 square miles (337,000 square kilometers). It is encircled by high mountains, which block moist air from reaching the desert for most of the year, creating extremely arid conditions that are too harsh for most plants.
"We found, for the first time, that human-led intervention can effectively enhance carbon sequestration in even the most extreme arid landscapes, demonstrating the potential to transform a desert into a carbon sink and halt desertification," study co-author Yuk Yung, a professor of planetary science at Caltech and a senior research scientist in NASA's Jet Propulsion Laboratory, told Live Science in an email.
Over 95% of the Taklamakan Desert is covered in shifting sand, meaning it has long been considered a "biological void," according to the study. The desert has been growing since the 1950s, when China underwent massive urbanization and farmland expansion. This conversion of natural land created the conditions for more sandstorms, which, in general, blow away soil and deposit sand instead, causing land degradation and desertification.
In 1978, China implemented the Three-North Shelterbelt Program, a huge ecological engineering project intended to slow desertification. Also called the "Great Green Wall," the project aimed to plant billions of trees around the margins of the Taklamakan and Gobi deserts by 2050. More than 66 billion trees have been planted in northern China to date, but experts debate whether the Great Green Wall has significantly reduced the frequency of sandstorms.
China finished encircling the Taklamakan Desert with vegetation in 2024, and researchers say the effort has stabilized sand dunes and grown forest cover in the country from 10% of its area in 1949 to more than 25% today.
Now, scientists have found that sprawling vegetation in the Taklamakan Desert's periphery is absorbing more carbon dioxide (CO2) from the atmosphere than the desert is releasing, meaning the Taklamakan may be transforming into a stable carbon sink.
The researchers analyzed ground observations of different vegetation-cover types, as well as satellite data showing precipitation, vegetation cover, photosynthesis and CO2 fluxes in the Taklamakan Desert over the past 25 years. They also used the National Oceanic and Atmospheric Administration's Carbon Tracker, which models CO2 sources and sinks globally, to bolster their findings.
The results, published Jan. 19 in the journal PNAS, show a long-term trend of expanding vegetation and rising CO2 uptake along the desert's edges that coincides both in time and space with the Great Green Wall.
Over the study period, precipitation during the Taklamakan Desert's wet season from July to September was 2.5 times higher than it was in the dry season, averaging about 0.6 inches (16 millimeters) per month. Precipitation enhanced vegetation cover, greenness and photosynthesis along the desert's margins, thereby lowering CO2 levels over the desert from 416 parts per million in the dry season to 413 ppm in the wet season.
Previous research indicated that the Taklamakan Desert may be a carbon sink, but those studies focused on CO2 that is absorbed by the desert's sand. They also suggested that sand is not a stable carbon sink under climate change, because rising temperatures can cause air in the sand to expand, which releases extra CO2.
"Based on the results of this study, the Taklamakan Desert, although only around its rim, represents the first successful model demonstrating the possibility of transforming a desert into a carbon sink," Yung said.
The Great Green Wall's potential to slow desertification remains unclear, but its role as a carbon sink "may serve as a valuable model for other desert regions," he added.
Noor, S., Jiang, X., Wang, X., Yang, J., Newman, S., Li, K., Li, L., Yu, L., Li, X., & Yung, Y. L. (2026). Human-induced biospheric carbon sink: Impact from the Taklamakan Afforestation Project. Proceedings of the National Academy of Sciences, 123(4), e2523388123. https://doi.org/10.1073/pnas.2523388123