HOTTEST SUMMER EVER IN SVALBARD: Temperature was 3C above ‘normal,’ including hottest day ever – but archipelago has been abnormally warm for the past three decades


Photo by Jesper Madsen /Norwegian Polar Institute

It’s not exactly a shock that a summer that saw Svalbard’s hottest day in recorded history is also the hottest summer in history, with an average temperature of three degrees Celsius above normal.

But while unusually warm, that “normal” is a somewhat skewed figure since it omits a marked period of overall warming during the past 30 years.


A graph shows the upward spike in average summer temperatures in Svalbard since 1899. Graph by Mai-Linn Finstad Svehagen / Norwegian Meteorological Institute.

The “summertime” (proverbial, since the official end of summer is Sept. 22) average of 7.2 degrees from June to August topped by a significant margin the previous record of 6.7 degrees set in 2015, the Norwegian Meteorological Institute reported in a press release Monday. The hottest single-day temperature in Svalbard of 21.7 degrees was set in Longyearbyen on July 25, only the second time in recorded history the 20-degree mark was exceeded.

“This year’s summer is extreme, but the temperature increase on Svalbard has been marked in the last 30 years, and differs completely from the previous 90 years,” said Ketil Isaksen, a climate researcher for the institute who has monitoring permafrost and climate change in the archipelago since the 1990s. “Not since we started with systematic temperature measurements on Svalbard in 1899 has it been as hot on the archipelago as this summer.”

Longyearbyen, where researchers say climate change is happening faster than anywhere on Earth, gained notoriety for a 111-month streak of above-average temperatures that finally ended in March. But the “average” temperatures for Svalbard are based on data from 1961 to 1990. The average will be “reset” for the years 1991 to 2020 beginning next year.


A polar bear eats a seal on the sea ice in the east Barents Sea in the spring of 2018. In addition to drastically shorter seasons for such hunting due to vanishing ice, bears also have the highest toxin levels anywhere on Earth due to increasing toxin levels in the seals for reasons attributed to climate change. Photo by Angelika Renner / Norwegian Polar Institute.

Summer temperatures in Svalbard always vary annually, of course, but until about 1990 the typical difference was  0.5 to 1 degrees.

“But during the 90s there was a marked change, and after 1997 we have not registered summers with average temperatures below normal,” Isaksen said. “We see a clear trend with warmer and warmer summers. This year’s summer is exceptional and it comes with a bad taste.”

Among the climate change impacts occurring – and accelerating in recent years – is permafrost frozen for thousands of years is thawing, resulting in sinkholes and damage to structures. It is also having profound impacts on wildlife from polar bears unable to hunt on rapidly vanishing sea ice to native marine life being wiped out as warming waters result in adverse conditions and migrating invasive species.

There are also major risks to settlements from landslides and avalanches, which perhaps most notably in recent years has resulted in the ongoing abandonment and demolition of about 250 residences and student dorms in Longyearbyen. The risk of landslides and various landscape changes will increase if the permafrost heats up or thaws. There are also geotechnical challenges associated with building and construction activities in permafrost, because both climate change and the installations themselves can lead to heating and poorer load-bearing capacity in the ground. Changes in the permafrost also affect the drainage patterns of the water.


A chart shows rising temperature in the permafrost in Svalbard since the 1990s. Chart by the  Norwegian Meteorological Institute.

Thawing layers are also releasing greenhouse gasses such as carbon dioxide and methane, the main contributors to global warming, according to the meteorological institute. Two boreholes drilled by researchers at Janssonhaugen – one of 102 meters and one of 15 meters, and among the first of their kind in Europe for monitoring permafrost – show a temperature increase of more than two degrees at a depth of 10 meters. The temperature measurements also show a steady increase over the past 20 years.

“When I started my permafrost studies in the late 90s, I did not think this was something I was going to experience,” Isaksen said “That the temperature deep down in the ground should rise so much and that today we see landscape changes on Svalbard, as a result of the permafrost thawing, is frightening. I and other researchers thought it would take much longer before we were able to see such changes.”