Recent and future CO2 emission trajectories and nature-based carbon neutrality potential in China under different SSP scenarios

China is the world’s largest anthropogenic CO 2 emitter, therefore, accurately evaluating China’s recent and future anthropogenic CO 2 emission trajectories, the nature-based carbon neutrality capacity (CNC), and investigating underlying driving factors hold significant importance to mitigating climate change. To provide robust projections of future CNC across China, we conducted an integrated assessment by combining multiple emission inventories, updated STIRPAT model under different Shared Socioeconomic Pathways (SSPs) scenario settings to simulate future CO 2 emissions to the end of this century, which were compared with ecosystem-based CO 2 sinks from 2021 to 2060. The main findings are as follows: (1) China’s annual anthropogenic CO 2 emissions are projected to peak between 2029 and 2032, with emissions (averages± SD) across SSP1-SSP4 scenarios reaching 1.18 (±0.14) × 10 4 Mt, while the Northwest and Northeast regions are anticipated to peak in the 2050s. Population size emerges as a significant driver, particularly in underdeveloped regions. (2) For mainland China, its CNC is projected to grow steadily from 21.7% ± 6.8% (21.9% ± 6.9%) in the 2030s to 31.3% ± 8.1% (28.6% ± 7.7%) in the 2060s in all SSPs, and large spatiotemporal disparities of CNCs were found across China. The Qinghai-Tibet Plateau and Southwest China emerge as critical carbon sink regions, with corresponding CNC of 351.2% ± 297.6% and 116.2% ± 37.1% during the 2050s–2060s, respectively. (3) Additionally, while China is expected to achieve its carbon peak around 2030, realizing national carbon neutrality still faces formidable challenges within the SSPs settings by only using nature-based solution, requiring sustained efforts in anthropogenic emission reduction. The estimates of clean energy shares show that under the SSP1-4 scenarios, the shares of clean energy under will reach 47.3% ± 4.2%, 41.6% ± 5.3%, 12.8% ± 9.1%, and 32.3% ± 5.4% by 2060. If China can achieve a clean energy share exceeding 80% before 2060, it can finally achieve carbon neutrality goal of CNC >100%. These findings indicate adaptive measures tailored to local conditions should be implemented and regional cooperation should be prioritized. This study provides important insights for unraveling regional emission reduction trends and carbon neutrality potential, laying a critical foundation for formulating region-specific policies to support China’s “dual carbon” goals.