In aeolian systems there is a fundamental difference between the behaviour of coarse sediments (sands) and fine sediments (dusts). Sand-sized material (63–2000 μm) travels predominantly by saltation, reptation and creep within the lowest levels of the atmospheric boundary layer (<3 m above the surface) and travels short distances. In contrast, dust-sized material, generally defined as <63 μm, is transported in suspension at a wide range of heights above the surface and can rapidly travel considerable distances. Dust plumes disperse as they travel away from source diffusing the concentration of sediment. Consequently, although there are clearly definable sources for dust emissions, these finer particles can be transported around the globe and their deposits can be both far removed from their origins and extensive. Every year up to three billion tonnes of dust are released into the atmosphere from the Earth’s surface. The spatial and temporal patterns of these dust emissions are often closely controlled by desert geomorphology, and in turn have an impact both directly and indirectly on the desert landscape and further afield