The Arctic tundra has a signature pattern of polygons due to complex interactions between soil and water—interactions that are being disrupted by the warming climate.

Subsurface ice wedges in Arctic permafrost create a distinct topography in the tundra that is disrupted when the ice wedges melt. Steadily rising average annual temperatures aren’t the only cause of ice-wedge melting; even brief periods of unusual warmth, such as what’s now regularly occurring in a single summer, can cause profound and irreversible ice-wedge degradation. The result is a draining and drying effect on the tundra, which can change how essential elements, like carbon and nitrogen, cycle through the system.