The Slowdown in Global Air-Pollutant Emission Growth and Driving Factors

Fine-particulate-matter pollution (PM2.5) is linked to millions of deaths annually. Consumption in one region can cause production and PM2.5 emissions in another, but the socioeconomic drivers of transboundary PM2.5 emissions are not fully understood. Here, we quantify the driving factors of primary-particle and oxidized-precursor emissions from 2004 to 2011 at global and regional scales. The results indicate that the growth rate of global PM2.5 emissions slowed from 2004 to 2011, mainly due to improvements in energy intensities and production efficiency. Improvements in the emission intensity of coal represent the main factor offsetting SO2 and NOx emissions, whereas emission controls implemented for industrial processes have largely contributed to reducing primary PM2.5 emissions. The net emissions embodied in East Asia's exports to developed countries declined, while that to developing countries increased rapidly. The analysis creates opportunities to involve both producers and consumers in co-mitigation of various pollutants.