Arid Climates and Desertification

Abstract

Covering nearly half of the earth's land surface, dry climates are extremely diverse in terms of temperature, patterns of precipitation, and physical appearance. A common attribute to all arid regions is low precipitation. Factors contributing to aridity include persistent high pressure, continentality, and location relative to either mountain ranges that block moisture‐laden winds or cool ocean waters that inhibit rainfall. Using Köppen's Climate Classification System, arid climates are designated as hot or cold deserts or as semiarid steppes. Arid and semiarid areas are susceptible to the impacts of drought but also to human degradation harmful to the productivity of vegetation called desertification. Although there is no consensus on its specific causes, desertification has been attributed to overgrazing, poor agricultural practices, and the indiscriminate use of fire, deforestation, and other activities that alter natural patterns of vegetation.