Drawing upon a quasi-natural experiment, this research investigates the influence of China’s National Digital Economy Innovation Development Pilot Policy on urban energy intensity. By examining a sample of 282 Chinese cities with the difference in differences (DID) approach, the findings provide robust empirical support for the proposition that digital economy pilot policies substantially reduce urban energy intensity. Furthermore, the policy’s effectiveness in lowering urban energy intensity differs across cities with varying administrative levels and population scales. The results suggest that the policy’s impact is more pronounced in ordinary cities (non-provincial capitals/municipalities) and in those with smaller populations. An examination of the underlying mechanisms reveals three principal pathways through which the policy affects energy consumption: (1) digital economic development, which promotes optimal resource allocation and enhanced energy intensity; (2) technological innovation, driving advances in green technologies and supporting sustainable industrial upgrades; and (3) economic agglomeration, which leverages economies of scale and industrial clustering to bolster energy efficiency. The conclusions underscore the necessity of expanding digital economy pilot zones, strengthening investments in digital infrastructure, and fostering greater technological innovation to sustain improvements in energy efficiency and environmental performance.

In the context of China’s “dual carbon” strategy, carbon productivity serves as a central in dicator for coordinating economic development with carbon emissions. While the digital economy reshapes spatial economic configurations and affects regional carbon productivity, its spatial interdependence and spillover effects remain insufficiently explored. Our study constructs composite indicators to measure both digital economy development and carbon productivity, examining 30 Chinese provinces from 2011 to 2022 using the super-efficiency SBM model and exploratory spatial data analysis. Spatial regression is applied to assess the spatial influences of the digital economy and the moderating role of industrial structure transforming. Results reveal that: (1) China’s carbon productivity has improved overall but with notable regional disparities; (2) a U-shaped linkage between digital development and carbon productivity is confirmed, with early-stage suppression and later environmental benefits; (3) industrial rationalization and upgrading significantly enhance this relationship, though structural frictions remain obstacles.

The National Big Data Comprehensive Pilot Zone (NBDCPZ) constitutes a landmark institutional initiative designed to advance and deploy data elements while strengthening governance capacity for environmental sustainability and low-carbon transition. Drawing on a panel dataset covering 285 Chinese cities at or above the prefectural level over the 2005–2023 period, this study capitalizes on the sequential rollout of the NBDCPZ to establish a quasi-natural experimental design. It employs a staggered difference-in-differences (DID) design to examine the policy’s causal effects on urban environmental quality—specifically, its effectiveness in curbing air pollution and carbon emissions—and further identifies the underlying mechanisms driving these effects and sources of contextual heterogeneity. The results demonstrate that the policy yields substantial benefits in curbing urban pollution and advancing carbon reduction; this conclusion remains robust across multiple sensitivity checks. Mechanism analysis reveals that the policy achieves synergistic gains in pollution reduction and carbon mitigation by promoting green innovation and reducing energy consumption, as well as by fostering digital industry agglomeration and accelerating digital innovation. Heterogeneity analysis shows significant structural variation in policy effects: non-resource-based cities exhibit more pronounced carbon mitigation effects, whereas resource-based cities, large cities, and old industrial bases demonstrate stronger pollution control effects.