Integrating explainable AI and causal inference to unveil regional air quality drivers in China

Air pollution poses a pressing global public health challenge, demanding a comprehensive understanding of its causes and evolving dynamics to inform effective control strategies. In China, significant spatial heterogeneity complicates the national air quality improvement process. Different regions exhibit varying pollution drivers, which makes uniform governance approaches less effective. Addressing this complexity requires a framework capable of capturing localized causal mechanisms. This study introduces the CADEPT (Causal Analysis-Detection-Explanation-Prediction-Threshold) multi-scale causal inference framework. Using nationwide air quality monitoring data from 2014 to 2022, the study integrates urban, socio-economic, and climatic datasets. It systematically investigates the driving forces and future evolution of the Air Quality Index (AQI) through four major stages: spatial heterogeneity detection, causal and interpretable inference, threshold identification, and scenario-based prediction. The results reveal the following key findings: (1) Local Moran's I detects significant spatial clustering of AQI, while spatial heterogeneity analysis uncovers region-specific influences from climate, emissions, and industrial structures. (2) Interpretability analysis, based on SHAP and TabPFN, uncovers nonlinear and region-specific contributions of key variables to AQI, highlighting climate's mitigating role and industry's aggravating effect. (3) Causal inference quantifies the true impacts of dominant factors, confirming that increases in temperature and precipitation improve air quality, while SO₂ emissions and industrial expansion worsen it. (4) Threshold analysis identifies critical response intervals, highlighting a synergistic amplification effect between meteorological conditions and emission factors. (5) Scenario simulations suggest that promoting low-carbon transitions and coordinated emission reductions are essential for achieving sustained nationwide air quality improvements.