Carbon emission intensity is an important index reflecting an entity’s low-carbon competitiveness. This paper presents an extended logarithmic mean divisia index (LMDI) model to dissect carbon intensity within China’s civil aviation from 1998 to 2019, revealing a significant reduction in CO₂ emissions per air transport revenue. It attributes this decrease to technological advancements, optimized fleet structures, and improved operational efficiencies, highlighting the impact of larger, more efficient aircraft and enhanced load factors. The study also explores economic factors influencing carbon efficiency, suggesting a comprehensive approach encompassing technological innovation and strategic operational improvements for sustainable aviation development.

The airline industry faces increasing pressure to balance economic performance with social and environmental responsibilities. This study investigates the influence of corporate social responsibility (CSR) on corporate value, incorporating the moderating role of carbon performance and the mediating effect of customer perception. A comprehensive CSR assessment framework based on ISO 26000 is developed across six dimensions: organizational governance, labor practices, the environment, consumer issues, fair operating practices, and community involvement. Panel data from 20 global airlines over 2017–2024 are used to test the proposed relationships. The results indicate that higher CSR scores are positively associated with corporate value and that customer perception, measured through Skytrax ratings, provides partial mediation. In addition, lower unit carbon intensity strengthens the positive CSR–value relationship, highlighting the importance of verifiable carbon performance in improving the financial returns to CSR. These findings distinguish broad CSR engagement from operational carbon outcomes and reinforce the role of carbon efficiency in sustainable airline strategy.