Climate change threatens Sámi region’s frozen peatlands

Climate change could wipe out palsa mires from the Sámi region and push the tree line higher into the fells, Yle reports. Forecasts indicate that average temperatures there will soon resemble those at the latitude of Jyväskylä.

Palsas are enormous peat mounds created by permafrost, with ice at their cores. At a palsa mire in Vaisjängä, Utsjoki, Kevo Research Station director Otso Suominen measures the depth of the thawed soil layer with an iron rod. The layer currently protecting the permafrost is about 60 centimetres deep.

Temperatures have been recorded at Kevo weather station since the 1960s. The year 2024 was the warmest in the measurement record, with both the accumulated temperature and the average temperature reaching their highest levels.

“The accumulated temperature matched the growing conditions in Jyväskylä. That was when the thawing of the permafrost clearly accelerated. The permafrost has not been able to recover since then,” Suominen says.

Palsa mires could disappear by the end of the century

Finland lies on the edge of the polar permafrost zone, between areas with permanent permafrost and areas without it. In Finland, permafrost occurs only in palsas.

A monitoring transect was established at the Vaisjängä palsa mire in 2021 to measure the permafrost. Of the 30 measuring points, 13 no longer contained permafrost this year, forcing researchers to establish an entirely new monitoring line.

Kevo Research Station hosts several studies at the palsa mire. Instruments measure temperatures and weather conditions, among other factors.

The station’s average temperature was minus 2 degrees Celsius in the 1960s and is now approaching zero. For palsa mires to survive, the average temperature would need to remain at minus 1 degree or colder.

“There is no sign of a decline in warming or in the amount of greenhouse gases. Palsa mires are disappearing quite rapidly because there is no change in sight in the warming trend. The pace appears to be accelerating,” Suominen says.

Up to half of the palsa mires have disappeared in recent decades. A doctoral study at the University of Oulu has predicted that they could vanish completely by the end of the century.

Pine trees are spreading into new areas

Climate change is also changing the landscape around reindeer herder Elli-Saara Äärelä’s cottage by the Repojoki River, near Lemmenjoki National Park. Pine trees have spread across the plot, replacing the dwarf birches that surrounded the cottage when it was built in 2008.

Äärelä has tried to clear the pines, but new saplings continue to emerge. Pine seedlings have also climbed higher on the fells, raising the tree line.

“The land is becoming denser with vegetation. What will that mean in the future?” Äärelä asks.

This summer, she noticed unfamiliar insects in a birch stand. The trees were covered with many green and white insects, and Äärelä is particularly concerned about what new insects could mean for reindeer.

“Will reindeer get new parasites or diseases? Those are things about the future that we do not know yet, but it is a fear,” she says.

Äärelä has also seen palsa mounds melt and noticed that the structure of the snow differs from previous decades. In recent years, snow has often fallen on unfrozen ground, whereas in the past the ground would first freeze before the snow arrived.

She says lichen, an important source of food for reindeer, has disappeared from the natural environment. Reindeer now have to be fed in many places, and she believes there is no return to the past.

Despite the challenges, Äärelä remains confident about the future of reindeer herding. She says the livelihood has always adapted to changing conditions, while expressing concern about what life will be like for children and grandchildren.