Measuring and optimizing pathways for regional economic and low-carbon coordination effects: A case study of the Yangtze River Economic Belt

Greenhouse gas emissions exacerbate the tension between economic development and low-carbon objectives, necessitating differentiated regional low-carbon development strategies. This study provides a preliminary analysis of the carbon emission characteristics of the Yangtze River Economic Belt. It investigates the relationship between economic output and emissions using the Tapio decoupling model. Regional green total factor productivity (GTFP) is assessed using a stochastic non-parametric data envelopment analysis (DEA) approach to clarify the output targets for regional low-carbon development. A multi-objective optimization model is developed, integrating the STIRPAT, NSGA-III, and TOPSIS methods to identify optimal development pathways for the next decade. Key findings include: (1) Carbon emissions initially increased before stabilizing, with over 80 % originating from the secondary sector. (2) Both weak and strong decoupling states were observed between GDP and the carbon emission decoupling index, with fewer provinces exhibiting strong decoupling. (3) The GTFP of downstream regions is significantly superior to that of upstream regions, and technological progress has a more pronounced impact on GTFP than changes in technical efficiency. (4) Forecasting and optimization results indicate that the economic development scenario is optimal, followed by the energy development scenario, whereas the low-carbon development scenario performs least favorably. Achieving the dual objectives of regional economic growth and emission reductions within the next decade is projected to require a confluence of factors: an 8 % annual economic growth rate, a decline in fossil fuel dependence to 53 % of the energy mix, and a contraction of the secondary sector's contribution to 47 %. • Analyzed the decoupling elasticity index among GDP, energy consumption, and carbon emissions. • Constructed an output-oriented regional low-carbon effect evaluation system. • Conducted multi-scenario predictions of future carbon emissions for different provinces. • The optimization model for the development of Economy-Energy-Carbon emission is constructed.