Underground ‘Zombie Fires’ Ignite Year-Round Threat Across Arctic Peatlands

In the remote boreal zones of Siberia, Canada and Alaska, a growing number of fires are surviving the winter months by burning beneath the snow, only to burst back onto the surface when spring melt provides oxygen. The process, termed “zombie fires,” occurs most often where peat soils are thick and rich in carbon; the frozen snow acts as an insulating blanket that protects the smoldering peat from freezing temperatures and moisture loss.

A study led by Rebecca Scholten of Vrije Universiteit Amsterdam, published in Nature, documents how these hidden flames can persist for months. Detection is difficult because standard satellite imagery cannot see through the cold snow, so crews now use heat-sensing drones and foot patrols to locate faint smoke plumes. Extinguishing the fires is costly and hazardous, requiring heavy machinery to turn over frozen peat and spread water-laden snow. Climate scientists warn that the thawing permafrost beneath these fires could release billions of tons of methane and carbon, accelerating global warming and creating a feedback loop that makes future fires more likely.