Emissions of Air Pollutants and Their Precursors
Atmospheric pollutants are mainly constituted with gases and aerosols, which result from anthropogenic and natural emissions. Anthropogenic emissions are mainly produced by human activities such as transportation and industry, while natural emissions include desert dust, wildfire, biogenic emissions, etc. Pollutants emitted from anthropogenic and natural sources have different characteristics but also interact with each other. Human activity can also influence natural sources. For example, human activity can lead to desertization that increases dust emissions; urbanization can change land covers that affect biogenic emissions and deposition and ventilation of air pollutants. On the other hand, natural pollutants such as dust can also enhance chemical production of anthropogenic pollutants. To quantify the contributions from anthropogenic and natural sources to the spatial and temporal variability of atmospheric pollutants will be very important for