Decoupling Effect of Carbon Emissions in the Yangtze River Delta Region Based on GDIM Factor Decomposition

Wan Youwei^1*Pan Binhui¹Xu Yaru¹Yu Yan^2*Yang Jiajia³Tang Xinfa^1*

• ¹Jiangxi Science and Technology Normal University, Nanchang, China
• ²Changsha Health Vocational College, Chang sha, China
• ³Industrial and Commercial Bank of China Limited, Chang Sha, China

Based on provincial-level energy balance sheets, a top-down estimation method was adopted to calculate the carbon emissions of the Yangtze River Delta region from 2008 to 2022.The extended Generalized Divisia Index Method (GDIM) was employed to decompose the driving factors of carbon emissions in the region. By integrating the GDIM decomposition approach with the traditional decoupling model, a new decoupling index model was constructed to conduct an in-depth study of the decoupling effects of carbon emissions in the Yangtze River Delta, scientifically quantifying the decoupling contributions of various factors. The results indicated that the total carbon emissions in the Yangtze River Delta region showed a trend of initial growth followed by a decline, while the Yangtze River Delta region generally exhibited a decreasing trend, with a reduction exceeding 65%.The influencing factors exhibited significant variations in their impact on regional carbon emissions: economic scale emerged as the primary driver of emission growth, while output carbon intensity served as the dominant mitigating factor; both energy consumption carbon intensity and energy intensity demonstrated substantial potential for future emission reduction. During the 2008-2022 period, most decoupling index values in the region were positive, reflecting measurable decoupling achievements, with Shanghai particularly achieving strong decoupling (index value:1.5603) during 2014-2016. Across five sub-periods, the decoupling effects consistently transitioned through "weak decoupling -strong decoupling -weak decoupling" phases, indicating more robust mid-term decoupling efforts that weakened subsequently. Output carbon intensity was identified as the key factor promoting decoupling, whereas energy scale constituted the main inhibiting factor. Consequently, policy recommendations emphasize developing region-specific carbon reduction strategies, enhancing support for low-carbon technology R&D and implementation, and continuously optimizing the energy structure.