Response of Aeolian Processes and Landforms to Climate Change and Variability

Abstract

Aeolian processes, involving erosion, transportation, and deposition of sand and dust by the wind, occur in a variety of environments, including the coastal zone, semi-arid and arid regions (e.g., cold and hot deserts), and agricultural fields in many climates. Changes in climate over the next century are likely to significantly affect aeolian processes globally via changes in precipitation, vegetation cover, wind strength, and sea level. For these reasons, the focus of this chapter is on the response of aeolian processes to climate change and variability on annual to decadal timescales during the period of climate observations, and over the past few centuries, with a look toward the response of these systems to future climate change. Because water is an important limiting factor in most dryland environments, aeolian processes are strongly affected by the amount, type, and temporal and spatial distribution of precipitation, which in turn affect the supply, availability, and mobility of sediment. Dust emissions, sand transport, and dune mobility are all strongly influenced by antecedent precipitation that affects soil moisture and vegetation cover; although specific responses are often complex and non-linear. The future responses can be evaluated via process-response models developed on the basis of empirical studies of the effects of modern climate variability (e.g., drought cycles) on aeolian processes, validated by reference to the geomorphic and sedimentary record of landscape response to late Holocene and historical climate change.