[Risk Analysis of Regional Carbon Imbalance Based on Carbon Budget Pattern and Its Transformation Trend]

Carbon budget accounting and identification of carbon imbalance risks contribute to revealing the impact mechanism and extent of human activity on the regional carbon budget. It is of great significance to conduct regional differentiated carbon governance and promote regional collaborative emission reduction. As a result, this study first constructed a research framework for regional carbon imbalance risk assessment based on carbon budget. Then, the carbon budget was calculated at a grid and county scale taking Henan Province as an example, and its spatio-temporal pattern was discussed. Finally, the regional carbon imbalance risk index was constructed to reveal the temporal and spatial evolution characteristics of carbon imbalance risk in Henan Province. The results showed： ① From 2001 to 2020, the carbon emissions in Henan Province increased from 232 million tons to 586 million tons. Spatially, it exhibited a gradually decreasing distribution pattern from the central areas to the periphery of each city. Carbon absorption showed a slight fluctuating increase trend （117 million-153 million） with a distribution feature of "higher in the west, lower in the east； higher in the south, lower in the north." ② The carbon source/sink ratio in Henan Province showed a characteristic of rapid growth followed by a gradual decline, reaching a peak of 5.14 in 2013. The carbon source/sink value in economically developed areas was significantly higher than that in economically underdeveloped areas. The regional differences in carbon balance transformation were evident, showing an overall "imbalance-neutralization-imbalance" trend. ③ During the study period, carbon imbalance risks in Henan Province gradually stabilized, and the number of districts and counties with a carbon imbalance risk index higher than 0.6 was 107 （68.2%） during 2016-2020. The high-risk areas of carbon imbalance mainly expanded from the Zhengzhou metropolitan area to the periphery along major transportation routes. ④ Future efforts should focus on establishing land spatial optimization and differentiated governance strategies, considering varying carbon imbalance risks across regions. This includes enhancing county-level cross-compensation mechanisms based on carbon imbalance risk assessments； mitigating regional carbon imbalances； and advancing regional collaborative emission reductions, carbon sequestration, and carbon neutrality goals.