The mechanisms and spatiotemporal patterns of the digital economy’s effect on China’s pollution reduction and carbon efficiency

The digital economy has emerged as a pivotal driver of China’s green and low-carbon transformation; however, its specific transmission mechanisms and spatiotemporal heterogeneity regarding environmental effects remain insufficiently explored. Utilizing panel data from 30 Chinese provinces (2011–2020), this study employs mediation analysis and Geographically and Temporally Weighted Regression (GTWR) to estimate the impact of the digital economy on pollution and carbon emissions. The results indicate that: (1) The expansion of the digital economy significantly mitigates environmental pressures, reducing pollutant and carbon emission intensities by 0.247 and 0.258 units per unit of growth, respectively. (2) Transmission mechanism analysis reveals that technological innovation is the primary channel, mediating 40.01% of the total effect, significantly outweighing the contribution of industrial structure optimization (16.85%). (3) The effects are spatially heterogeneous, with stronger pollution reductions in northeastern and eastern provinces and larger carbon-intensity reductions in western provinces. (4) The synergistic effects strengthened from 2016 to 2020. The earlier spatial misalignment between pollution control and carbon mitigation was effectively eliminated.