What Are Arctic Fires and What Causes Them?

Although we tend to associate a warming Arctic with issues like disappearing glaciers and sea level rise, the territory characterized by polar bears and icy oceans is actually facing another staggering threat: wildfires.

Arctic fires are setting new records each year. They’re growing larger, faster, and becoming more frequent as temperatures continue to rise. Secluded, dry conditions make the unique landscape more susceptible, while carbon stored in its extensive peatland ecosystems release massive amounts of CO2 as they burn.

Back in 2013, forest fires in the Arctic exceeded the pattern, frequency, and intensity of wildfire limits from the past 10,000 years. And a 2016 study published in the journal Ecography predicted that fires in both the boreal forests and in the Arctic tundra will increase fourfold by 2100. Seeing as these areas cover 33% of the global land area and store about half the world’s carbon, the consequences of Arctic fires reach far outside the zone above the polar region.

What Causes Wildfires in the Arctic?

Fires are a natural part of wild ecosystems, including the Arctic. Black and white spruce trees in Alaska, for example, depend on ground fire to open cones and expose seedbeds. Occasional wildfires also clear dead trees or competing vegetation from the forest floor, breaking down nutrients to the soil and allowing new plants to grow.

However, when this natural fire cycle is accelerated or altered, fires can create more serious ecological issues.

Arctic fires are especially dangerous due to the region’s high concentration of peat — decomposed organic matter (in this case, hardy species of mosses) — found beneath the soil. When frozen peatlands melt and dry up, what’s left over is highly flammable, with the potential to set ablaze with a simple spark or lightning strike. Not only are peatlands critical for preserving global biodiversity, they also store more carbon than all other vegetation types in the world combined.

Whereas wildfires in the Western United States mostly release carbon through the burning of trees and shrubs rather than organic matter in the soil, the heavy peatlands of the Arctic produce a combination of all three. Liz Hoy, a boreal fire researcher at the Goddard Space Flight Center explains this phenomenon in an interview with NASA,

"Arctic and boreal regions have very thick soils with a lot of organic material — because the soil is frozen or otherwise temperature-limited as well as nutrient-poor, its contents don’t decompose much. When you burn the soil on top it’s as if you had a cooler and you opened the lid: the permafrost underneath thaws and you’re allowing the soil to decompose and decay, so you’re releasing even more carbon into the atmosphere."

Arctic wildfires may not be destroying much property, but that doesn’t mean they aren’t doing any damage. “I sometimes hear ‘there aren’t that many people up there in the Arctic, so why can’t we just let it burn, why does it matter?’” Hoy goes on. “But what happens in the Arctic doesn’t stay in the Arctic — there are global connections to the changes taking place there.”

In addition to directly emitting carbon into the atmosphere, Arctic fires also contribute to thawing permafrost, which can lead to increased decomposition, putting the areas in even more increased risks of fires. Fires that burn deeper into the ground release generations-old carbon stored in boreal forest soil. More carbon in the atmosphere leads to more warming, which leads to more fires; it’s a vicious cycle. 

After a record breaking fire in 2014, a team of researchers from Canada and the U.S. collected soil from 200 wildfire locations around Canada’s Northwest Territories. The team found that forests in wet locations and forests over 70 years old contained a thick layer of organic matter in the ground protected by older “legacy carbon.” The carbon was so deep in the soil that it hadn’t been burned in any previous fire cycles. While boreal forests had previously been considered “carbon sinks” that absorb more carbon than they emit on the whole, bigger and more frequent fires in these areas could reverse this.

The Siberian Fires

Since July 2019 was the hottest month on record for the planet, it only makes sense that the month would also produce some of the worst wildfires in history. The summer months of 2019 saw over 100 widespread, intense wildfires across the Arctic Circle in Greenland, Alaska, and Siberia. Fires in the Arctic made headlines when scientists confirmed that over 50 megatons of CO2, equivalent to what the country of Sweden emits in an entire year, were emitted in June. In 2020, however, Arctic fires released 244 megatons of carbon dioxide between January 1st and August 31st — 35% more than in 2019. The smoke plumes covered an area larger than a third of Canada.

A majority of the 2020 Arctic fires took place in Siberia; the Russian Wildfires Remote Monitoring System assessed 18,591 separate fires in the country’s two easternmost districts. Siberia’s 2020 wildfire season got off to an early start — possibly due to zombie fires waiting patiently underground. A total of 14 million hectares burned, mostly in permafrost zones where the ground is normally frozen year-round.

What Will Happen if the Arctic Continues to Burn?

As the fires spread, they launch fine particulate matter into the air in the form of black carbon, or soot, that’s as harmful to humans as it is to the climate. Spots where the soot is deposited onto snow and ice can decrease the area’s “albedo” (level of reflectivity), leading to faster absorption of sunlight or heat and increased warming. And for humans and animals, the inhalation of black carbon is associated with health problems.

According to a 2020 NOAA study, Arctic wildfires occur primarily in the boreal forest (also known as the taiga biome, the world's largest terrestrial biome). By studying trends in air temperature and wildfire fuel availability between 1979-2019, they found that conditions are becoming more favorable for fire growth, intensity, and frequency. Black carbon or soot from wildfires can travel up to 4,000 kilometers (close to 2,500 miles) or more, while combustion removes the insulation provided by soil and accelerates permafrost thawing. 

Rapid thawing can result in more locally based issues like floods and rising sea levels, but also affects the overall biological composition of the land. The Arctic is home to diverse species of animals and plants, many of which are endangered, that have adapted to live in the delicately balanced ecosystem of cold temperatures and ice.

Moose are more likely to change their migration patterns during the decades after a large fire to feed off the young vegetation growing back. Caribou, on the other hand, depend on slow growing surface lichens that take much longer to accumulate after a serious wildfire. The smallest shift in a prey species annual range can disrupt the other animals and people who depend on them for survival.

A 2018 study in Nature found that warmer Arctic temperatures are supporting new species of plant life; while that might not sound like a bad thing, it means that increased development may not be far behind. As different parts of the world become less hospitable and others become more so, climate change effects in the Arctic Tundra could potentially lead to a massive refugee crisis.

What Can We Do?

Firefighting in the Arctic presents some pretty unique challenges. The Arctic is vast and sparsely populated, so fires often take much longer to extinguish. Plus, a lack of infrastructure in wild Arctic regions means firefighting funds are more inclined to be directed elsewhere where there’s more risk to life and property. Frigid conditions and remote areas also make it difficult to access the areas where fires burn.

Since stopping these fires from spreading seems to treat the symptoms rather than the actual cause, it would appear the most important thing we can do is mitigate the overall climate crisis at its sources. While presenting the Special Report on the Ocean and Cryosphere in a Changing Climate (SROCC), WWF Arctic Programme Director Dr. Peter Winsor said that the negative changes occurring in the polar regions are not without hope:

"We can still save parts of the cryosphere — the world’s snow- and ice-covered places — but we must act now. Arctic nations need to show strong leadership and step forward with their plans for a green recovery from this pandemic to ensure we can achieve the Paris Agreement goal of 1.5°C of warming. The world is critically dependent on healthy polar regions. The Arctic, with its four million people and ecosystems, needs our help to adapt and build resilience to meet today’s reality and future changes to come."