Wildfires in the boreal forests of the far Northern Hemisphere are surviving the winter and picking up again in spring according to a new study published in Nature. The study found that instances of overwintering fires were increasing, though they are still relatively low at the moment.
The study was carried out by a team of scientists from the Netherlands in collaboration with scientists from Alaska. They focused on far Northern Hemisphere forests, where the climate is warming much faster than the rest of the world. Researchers established that the “zombie fires” continue burning under the snow covering and erupt back to life in spring.
According to the study, zombie fires were responsible for about 0.8% of forest areas burned in the boreal forests between 2002 and 2018. However, researchers found that some years had higher damage percentages, depending on the warmth of the summers. In fact, there was one year when zombie fires accounted for 38% of the burn area. Scientists have now warned that continued global warming may lead to increased damage from zombie fires.
Sander Veraverbeke, a landscape ecologist at Vrije Universiteit Amsterdam and one of the study’s authors, discussed the causes of these fires. “We know that fires can start in the fire season by lightning and humans. Now we can have another cause of burned area. If it happens near a fire scar from the year before, early in the season, and there’s no lightning and it’s not human, then it’s an overwinter fire,” Veraverbeke said.
Researchers also say that such fires put the boreal peat at risk. The boreal peat protects the permafrost below, which holds large volumes of sequestered carbon. If zombie fires increase, the region could release harmful amounts of greenhouse gases.
“I think a general perception of people when they think about forest fires, they think about trees burning,” Veraverbeke said. “But in these areas in the high north, in the boreal forest, about 90% of the carbon that is emitted comes from the soil.”
In a different study, scientists also established that climate change might lead to increased lightning strikes in the far Northern Hemisphere region, which would, in turn, cause more fires.
Via The Guardian
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