Research on the impact of the digital economy on carbon emission efficiency in China’s food cold chain logistics: the mediating role of green technological innovation

Introduction The food cold chain logistics industry is a significant source of carbon emissions in food systems due to its heavy reliance on refrigerated power consumption. However, the mechanisms through which the digital economy promotes low-carbon transformation in this sector, particularly the mediating role of green technological innovation, remain insufficiently explored. Methods Using panel data from 30 provinces in China from 2013 to 2022, this study employs a non-radial, non-angular SBM-DEA model incorporating dual undesirable outputs (carbon emissions and food loss) to measure carbon emission efficiency. Two-way fixed effects models examine direct effects, bootstrap mediation tests assess indirect pathways, and Hansen panel threshold models evaluate the nonlinear moderating role of cold chain infrastructure. Results The digital economy significantly enhances carbon emission efficiency in food cold chain logistics, with an estimated coefficient of 0.124 ( p < 0.01). Green technological innovation partially mediates this relationship, with the indirect effect accounting for 40.32% of the total effect. A sequential mediation pathway of green technological innovation → food loss reduction → carbon emission efficiency improvement is confirmed. Cold chain infrastructure exhibits a threshold effect (γ = 0.418), with the marginal effect rising from 0.054 to 0.183 above the threshold. Heterogeneity analysis shows the carbon reduction effect is strongest in developed cold chain regions (0.197) and insignificant in lagging regions (0.041). Discussion These findings reveal that digital transformation promotes low-carbon development in food cold chain logistics through both direct efficiency gains and indirect innovation channels. The threshold effect highlights the complementary role of physical infrastructure in enabling digital carbon reduction. Targeted policy support for cold chain infrastructure investment, particularly in underdeveloped regions, is essential to unlock the full carbon reduction potential of the digital economy.