"Zombie" fires become a danger: hidden climate killers

In the Arctic, the permafrost soil is thawing more and more due to climate change.

This can cause so-called "zombie" fires that can even survive in the peat soil for years.

Arctic - In general, fires in the Arctic are not a new phenomenon: In Siberia and Alaska, fires repeatedly occur in drier taiga and tundra areas in summer.

So far, however, most of the permafrost areas beyond the Arctic Circle have been considered largely fire-resistant.

But climate change is causing the permafrost to thaw in the Arctic.

As a result, huge forest fires occur more and more frequently.

Permafrost soils are soils that have not thawed for a period of at least two years.

The permafrost can reach a depth of 1500 meters and can be found in cold climates at high latitudes and in the high mountains.

The ice acts like cement and holds the ground together.

“Zombie” fires in the Arctic: Fires hibernate underground

The thin layer of thaw above the permafrost does thaw in summer, but then freezes again in winter.

Forest fires that break out in summer are usually put out by the arctic winter.

Due to the thawing permafrost, the fires are now able to “hibernate” underground.

In doing so, they spread undetected in the valuable CO2 storage peat.

In 2020, the scientist Jessica L. McCarty and her team published an article on such “zombie” fires in the Arctic in

.

According to this, such fires can smolder underground for months or even years.

Even in winter and spring, these hidden fires remain alive despite frost and snowmelt; they can often only be recognized by the smoke rising from the surface of the earth.

"Zombie" fires can "further fuel global warming"

"One of the fascinating aspects of these zombie fires is that they don't need new triggers like lightning or campfires, but are a continuation of the fires from the previous year," explain McCarty and her team.

The “zombie” fires can further drive global warming.

"The record temperatures and the associated fires have the potential to turn the important carbon sink of permafrost into a source of carbon - and thus further fuel global warming," warns scientist Thomas Smith.

The 2021 Nobel Prize for Physics also shows that climate is playing an increasingly important role in society and science.

Because this went to three researchers who were working on models of the earth's climate.