Zombie Fires: The Undead Wildfires Smoldering Beneath the Snow

Introduction: The Undead Wildfires

Deep within the world’s northernmost forests, a chilling phenomenon is taking hold. They’re called ‘zombie fires’—wildfires that don’t die with the winter snow. Instead, they burrow deep into carbon-rich peat and soil, smoldering like embers for months under a blanket of ice and snow, only to roar back to life as the spring thaws the landscape. This is not a horror story; it’s a stark and escalating reality of our warming planet.

A Disturbing New Reality: The Rise of Multi-Year Fires

What was once a rare occurrence is now becoming alarmingly common. At the beginning of 2024, British Columbia reported over 100 active zombie fires left over from the previous season. Some of these stubborn blazes have now persisted for nearly three years, a situation that has experts on high alert. Mike Flannigan, a wildland fire professor at Thompson Rivers University, emphasizes the gravity of the situation: “What we haven’t seen is fires burn through multiple winters. We are in uncharted territory.”

The Science Behind the Smolder

Zombie fires thrive in the organic, carbon-dense soils of Arctic and boreal ecosystems. As hotter, longer summers dry out this peat, it becomes the perfect fuel for a slow, smoldering combustion that can survive the harsh winter. As Professor Lori Daniels of the University of British Columbia explains, the fires “move into the organic soil matter and smoulder. It’s a very slow, but hot, combustion through a prolonged period and then they resurface.”

Adding a new layer of complexity, groundbreaking research from June 2024 suggests a more direct cause. Scientists now theorize that the sheer rate of atmospheric warming can heat these peat soils to the point of spontaneous combustion, igniting them from below without any initial surface spark. This highlights a terrifying new pathway for wildfire ignition driven solely by accelerated climate change.

By the Numbers: The Alarming Impact of Zombie Fires

The data paints a clear picture of a growing threat:

• Explosive Growth: Between 2002 and 2018, overwintering fires were responsible for less than 1% of the total area burned in Alaska and Canada’s Northwest Territories. In recent years following severe fire seasons, that number has skyrocketed to as high as 38%.
• Early Season Ignition: In an unprecedented start to Canada’s 2024 fire season, the majority of the first 500,000 hectares burned were attributed to these holdover fires from the previous year.
• Massive Carbon Release: The Arctic’s peatlands are one of the world’s largest natural carbon sinks. When they burn, they release gigatons of stored carbon and methane into the atmosphere, further accelerating global warming.

A Vicious Cycle: Climate Change and Future Outlook

The emergence of zombie fires signals a dangerous climate feedback loop. The Arctic is warming at a rate faster than anywhere else on Earth. This warming thaws permafrost and dries out soils, creating ideal conditions for zombie fires to persist. These fires then release immense quantities of greenhouse gases, which in turn fuels even more rapid warming. As landscape ecologist Sander Veraverbeke notes, “The sheer fact that this is happening is already pretty crazy and shows how fast this region is changing because of climate change.”

Fighting these subterranean blazes is a perilous task. The ground can be unstable and prone to collapse, and locating the deep, smoldering hotspots is incredibly difficult, making extinguishment a monumental challenge.

Conclusion: A Smoldering Warning

Zombie fires are more than just a scientific curiosity; they are a smoldering warning from our planet. They represent a fundamental shift in our climate system, where wildfire seasons are starting earlier, lasting longer, and even persisting through the winter. This ‘undead’ threat underscores the urgent need for global action on climate change before more of these critical ecosystems are locked in a self-perpetuating cycle of fire and warming.