ABSTRACT
Aerosols are a collection of various microscopic airborne solid (e.g. soot) or liquid (e.g. mist) particles. These particles may be of natural (dust storms, sea spray, forest fires, volcanic eruptions) or anthropogenic origin (such as combustion of fossil fuels, construction/mining dust, agriculture, biomass burning). Some sources, such as soot and sulfates from fossil fuel combustion (the largest source of aerosols) are clearly anthropogenic, while others, such as wind-blown dust from land altered for agriculture are difficult to distinguish between natural and anthropogenic origin. This uncertainty of origin makes determining the impact of aerosols on climate change difficult as natural aerosols sources are part of the preindustrial climatic equilibrium.1
