A growing number of Arctic underground cellars are being rendered unreliable as global warming and other modern factors force changes to an ancient way of life.

Permafrost thaw is affecting houses, roads, and ice cellars.

HEALY, ALASKA—Bitter winters still dominate life in the Alaskan interior, but a practiced eye can spot the signs of a warming climate, particularly in the ground. Beneath the rolling fields of tussock scattered just north of the Alaska Range, what was once permanently frozen is starting to thaw. The impacts could ripple across the planet.