The map show six common delineations. The Arctic circle is sometimes referred to as defining the Arctic, while the 10 °C has been the traditional definition used in many geography school books. Similarly the treeline has been used as a delimiting line for the Arctic in schoolbooks in biology and ecology. The AHDR (Arctic Human Development Report) emphasizes that the Arctic is a homeland for peoples, and therefore includes the social, economic, political, and ecological processes that are the critical properties for the functioning of the Arctic System. The AMAP (Arctic Monitoring and Assessment Programme) focuses on the environmental conditions in the Arctic, and therefore chooses to use a definition based on the general function of the Arctic environmental system. CAFF (Conservation of Arctic Flora and Fauna), however, focuses on the Arctic from an ecosystem point of view.
The fact that not one definition serves all purposes highlights show the complexity of the Arctic, and the need to be precise when referencing it in a specific manner.
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