The Arctic, despite its image of endless ice and snow, includes vast areas classified as deserts. These “polar deserts” challenge common assumptions, extending the definition of arid environments beyond hot, sandy landscapes to Earth’s frigid extremes. Significant portions of the Arctic meet the scientific criteria for a desert.
What Makes a Desert a Desert
A desert is defined by its lack of precipitation, not high temperatures. Scientifically, a region is classified as a desert if it receives less than 250 millimeters (approximately 10 inches) of annual precipitation, including both rain and snow. This low moisture means insufficient water for lush plant growth and sparse vegetation. While many deserts, like the Sahara, are characterized by intense heat, deserts can also be cold, with polar deserts being a prime example.
The amount of moisture available for life is the critical factor, not its form or ambient temperature. In arid environments, evaporation often exceeds precipitation, contributing to dryness. This imbalance creates challenging conditions for ecosystems, regardless of whether the region is hot or cold.
The Arctic’s Arid Reality
Despite its vast ice sheets and snow cover, much of the Arctic experiences extremely low annual precipitation, classifying it as a polar desert. Existing ice is accumulated frozen water, not new annual moisture. Many Arctic regions receive 100 to 250 millimeters of annual precipitation, with areas like the North Pole and Canadian Arctic Archipelago receiving as little as 150 millimeters. The interior of the central and northern Greenland ice sheet is among the driest parts of the Arctic, with annual totals ranging from under 100 to about 200 millimeters.
Several atmospheric conditions contribute to this aridity. Cold air holds less moisture than warm air, limiting available water vapor for precipitation. Many Arctic areas are also dominated by persistent high-pressure systems, such as the Beaufort High. These systems involve sinking air, which warms and dries as it descends, preventing cloud formation and precipitation. Distance from major moisture sources, like open oceans, further reduces potential snowfall or rainfall.
Surviving the Arctic Dryness
Life in the Arctic’s polar deserts exhibits remarkable adaptations to cope with the extreme cold and the pervasive dryness. Plants in these environments have evolved specific features to conserve the scarce moisture available. Many Arctic plants, such as lichens, mosses, and dwarf shrubs, possess small, thick, or needle-like leaves with waxy coatings to minimize water loss through evaporation. Cushion-like growth forms also help trap moisture and provide protection from the wind. Extensive root systems enable plants to access what little water exists in the frozen ground, while some species are evergreen, retaining nutrients and moisture over long periods.
Arctic animals also display specialized strategies for survival in arid, frigid conditions. Polar bears and Arctic foxes have thick fur and layers of blubber, which provide insulation against the cold and indirectly reduce the metabolic need to generate heat, thus conserving water. Smaller mammals, such as lemmings, burrow into the snow or ground for more stable temperatures and higher humidity. Some animals produce highly concentrated urine to minimize water loss, or obtain metabolic water from breaking down fats in their diet, further reducing their reliance on direct water intake. These adaptations demonstrate how life persists in the Arctic’s dry and cold desert environment.