What Factors Dominate the Change of PM_2.5 in the World from 2000 to 2019? A Study from Multi-Source Data

As the threat to human life and health from fine particulate matter (PM_2.5) increases globally, the life and health problems caused by environmental pollution are also of increasing concern. Understanding past trends in PM_2.5 and exploring the drivers of PM_2.5 are important tools for addressing the life-threatening health problems caused by PM_2.5. In this study, we calculated the change in annual average global PM_2.5 concentrations from 2000 to 2020 using the Theil-Sen median trend analysis method and reveal spatial and temporal trends in PM_2.5 concentrations over twenty-one years. The qualitative and quantitative effects of different drivers on PM_2.5 concentrations in 2020 were explored from natural and socioeconomic perspectives using a multi-scale geographically weighted regression model. The results show that there is significant spatial heterogeneity in trends in PM_2.5 concentration, with significant decreases in PM_2.5 concentrations mainly in developed regions, such as the United States, Canada, Japan and the European Union countries, and conversely, significant increases in PM_2.5 in developing regions, such as Africa, the Middle East and India. In addition, in regions with more advanced science and technology and urban management, PM_2.5 concentrations are more evenly influenced by various factors, with a more negative influence. In contrast, regions at the rapid development stage usually continue their economic development at the cost of the environment, and under a high intensity of human activity. Increased temperature is known as the most important factor for the increase in PM_2.5 concentration, while an increase in NDVI can play an important role in the reduction in PM_2.5 concentration. This suggests that countries can achieve good air quality goals by setting a reasonable development path.