The air we breathe: An In-depth analysis of PM 2.5 pollution in 1312 cities from 2000 to 2020.

In recent decades, the phenomenon of rapid urbanization in various parts of the world has led to a significant increase in PM 2.5 concentration, which has emerged as a growing social concern. In order to achieve the objective of sustainable development, the United Nations Global Sustainable Development Goals (SDGs) have established the goal of creating inclusive, safe, resilient, and sustainable cities and human habitats (SDG 11). Goal 11.6 aims to decrease the negative environmental impact per capita in cities, with an emphasis on urban air quality and waste management. However, the global distribution of PM 2.5 pollution varies due to disparities in urbanization development in different regions. The purpose of this paper is to explore the global spatial distribution and temporal variation of PM 2.5 in cities with populations greater than 300,000 from 2000 to 2020, to gain insight into the issue. The findings indicate that PM 2.5 concentrations are expected to continue increasing as urbanization progresses, but the rate of evolution of PM 2.5 concentration varies depending on the continent, country, and city. From 2000 to 2020, PM 2.5 concentration increased significantly in Asia and Africa, with the majority of the increased concentrations located in Asian countries and some African countries. On the other hand, most European and American countries had lower PM 2.5 concentrations. The results of this study have the potential to inform urbanization policy formulation by providing knowledge about the spatial distribution of PM 2.5 pollution during global urbanization. Addressing the issue of PM 2.5 pollution is critical in achieving SDG 11.6 and promoting sustainable and coordinated development in cities worldwide.