Anyone who has followed the news from the Arctic in recent years has almost regularly come across news about massive bush and tundra fires that have been reported in almost all regions of the Arctic. Especially in large parts of Russia’s central and eastern regions, commonly known as Siberia, flames blazed for most of the summer. A study has looked at the reasons for these long-standing recurring fires and their extent, and has come across a number of factors.
A northward shift of the polar jet stream (also known as the Arctic Front), coupled with an increasingly early snowmelt and stronger and northward-shifted lightning activity are the reasons why fires had been so frequent and severe in the eastern and central parts of Russia over the past twenty years. This is the result of the study by PhD student Rebecca Scholten and Professor Sander Veraverberke of the Free University of Amsterdam, who, together with other team members, had investigated the causes and factors behind the fires. The work was published in the journal Science.
The research team studied fires in the eastern part of Russia in the period between 2001 and 2021. According to the results, the fires that affected the region in recent years were the most severe, accounting for about 41 percent of the total area burned over the 20-year period. They were mostly driven by the northward shifting polar jet stream, which was responsible for higher than average temperatures and drought in the areas. These occurred because the air masses had not moved properly due to the shift in the airflow, and the snow still lying in Siberia thawed faster and earlier. Thus, the soil underneath was exposed to sunlight longer and was more susceptible to fire. The fires, some caused naturally by lightning strikes and some human-caused, had not only been devastating to the region’s plant life, but had also re-released large amounts of greenhouse gases stored in the soil. Furthermore, they also affected the permafrost, which remains thawed in the long term and no longer serves as a CO2 sink, but becomes a source of greenhouse gases through degradation processes.
Other studies have also shown that fires have a major impact on more than just the plant life and the few people who live there. Wildlife is also threatened by the increasing number of fires. This is because especially large and mobile species such as bears, reindeer or wolves evade the fires to the north (also favored by the warming of these regions) and thus encounter Arctic species. This encourages competition for food and space, and is an additional stressor for warming animals.
Overall, the researchers believe the region will face even more frequent intense fires in the future
Dr Michael Wenger, PolarJournal
More on the topic
