A new study published in Nature Climate Change finds that China’s carbon sinks resulting from land-use change over the past four decades have been significantly underestimated in global assessments. The research, conducted by an international team led by Sun Yat-Sen University, shows that China shifted from a carbon source due to land clearing and degradation to a major carbon sink since the 1990s due to decades of large-scale reforestation and land management improvements. 

The study, led by corresponding authors Professor Zhangcai Qin, Assistant Director of the Future Earth China Hub, and Professor Wenping Yuan, analyzed carbon fluxes linked to land-use change between 1981 and 2020, using two independent models and a novel dataset integrating remote sensing with China’s National Forest Inventory. “We used a dynamic global vegetation model and a book-keeping model (the LUCE model) that we recently developed” noted Yakun Zhu and Xiaosheng Xia, lead authors of the study, “The land-use data is also updated to identify the forest coverage changes documented in the national inventory.”

What the research shows

The key findings show that China’s net carbon flux from land-use change alone transitioned from emitting carbon in the 1980s to absorbing it by the 1990s. Over the past 40 years, these activities removed a cumulative of 7.3 billion metric tons of CO₂ with an annual average sink of 0.5 billion tons of CO2 per year from 2001. The annual sink accounts for over one-third of the nation’s total land carbon uptake that also includes all native vegetation not under management. This amount of CO2 rivals the annual emissions of countries like Russia or Japan. While reforestation and afforestation were major contributors, non-forest land-use changes—such as grassland restoration and agricultural transitions—also played a critical role in certain regions, underscoring the complexity of China’s landscape management.

The findings challenge previous global assessments, which often overlook regional nuances. For instance, international assessments have underestimated China’s carbon sinks by failing to incorporate high-resolution and local data on land-use policies that led to reforestation and afforestation. “This ground-breaking study is a great example of the need to develop region-specific data and modeling to accurately evaluate carbon budgets and inform the development of climate mitigation strategies,” said co-author Professor Josep Canadell, the Executive Director of Global Carbon Project, a Future Earth Global Research Network, that aims to assess global greenhouse gas budgets from all sources and sinks of greenhouse gases. 

China’s decades-long nature-based restoration projects, including many reforestation campaigns to prevent and combat land degradation, have been central to this shift. Since the 1970s, China has initiated several ecological projects, such as the Natural Forest Protection Project and The Grain for Green Program, and the deforestation rate has decreased substantially. The results also bolster China’s climate pledges, suggesting its terrestrial ecosystems are absorbing far more CO₂ than previously recognized.

localized action can yield big results

Researchers urge nations to adopt high-resolution, regionally tailored data in national carbon accounting. “Accurate and high-resolution assessments of land-use change are vital for efficient natural preservation and equitable climate governance,” Professor Zhangcai Qin and Professor Wenping Yuan noted. “China’s experience demonstrates how localized actions can yield globally significant impacts.” 

This study refines our understanding of carbon dynamics and reinforces the importance of integrating national data into international climate frameworks—a critical step for the Transparency Framework of Paris Agreement to achieving net-zero goals worldwide.

The study: Zhu Y, Xia X, Canadell J G, Piao S, Lu X, Mishra U, Wang X, Yuan W, Qin Z. China’s carbon sinks from land-use change underestimated, Nature Climate Change. 2025, https://www.nature.com/articles/s41558-025-02296-z.