This study explores the linkages between financial activities and ESG factors to support sustainable development goals, using a sophisticated fsQCA-ANN method to analyze the impact of green finance on carbon intensity. Findings reveal nine causal paths contributing to carbon reduction, highlighting intricate interactions among factors. Key insights include the positive effect of a conducive financial environment, increased environmental investment, and the integration of green finance atmosphere, environmental investment, financial regulatory expenditure, and local digital economy. The Green Finance Development Index (GFDI), Digital Inclusive Finance Index (DIF), and Financial Value Added (FV) further enhance environmental innovation and technology transfer, aiding the transition to a low-carbon economy. The ANN methods show that the impact of green finance on decarbonization is complex and non-linear. This study underscores the necessity of considering these interactions for promoting sustainable development and reducing carbon emissions, providing theoretical and empirical foundations to support sustainable development goals.