The small Siberian town of Verkhoyansk is notorious for its extremely cold temperatures: winter temperatures often fall below – 50 ° Celsius. But on June 20, temperatures in the city soared to 38 ° C (100.4 ° Fahrenheit). If certified by the World Meteorological Association, this is the hottest temperature ever recorded north of the Arctic Circle. Previously, Verkhoyansk had witnessed extreme heat: on July 25, 1988, the town reached a 37.3 ° C (99.1 ° F) record. The new high, which breaks the 32-year record, comes on the heels of a historically hot May around the globe, and particularly in Siberia, which is in the grip of a persistent heat wave.
Worldwide, May was 0.63 degrees C warmer than average May temperatures from 1981 to 2010, enough to set a new record, according to the European Union’s Copernicus Climate Change Service. Worldwide, May was 0.63 degrees C warmer than average May temperatures from 1981 to 2010, enough to set a new record, according to the European Union’s Copernicus Climate Change Service. But in several regions of Siberia, especially in northwestern Siberia, May temperatures were as high as 10 degrees Celsius above average.
The phenomenon was so evident that the heat wave in the area will reflect a 1 in a 100,000-year event — at least in a world without climate change, climate scientist Martin Stendel of the Danish Meteorological Institute in Copenhagen, tweeted on June 9. Nevertheless, with climate change, these Arctic heat waves are likely to become more frequent, along with melting permafrost and growing wildfires.
The latest measurement illustrates how the Arctic zone heats twice as quickly as the rest of the world, a phenomenon known as Arctic amplification. When paired with NASA evidence from 1880, the researchers say that this six-month period is likely to be unprecedented within the last 140 years. But the new record did not occur in a vacuum: it is part of the long-term pattern of increasingly hot temperatures in Siberia related to climate change, and a broader, even more troubling pattern of accelerated warming over the last few decades across the Arctic region. Here are four things to keep in mind about this new Arctic record.
Siberia has been sweltering under months of unprecedented warmth.
Much of this record-breaking heat is the result of warming in Siberia, where May temperatures were as high as 10 degrees Celsius above normal, says climate scientist Martin Stendel of the Danish Meteorological Institute in Copenhagen.
This devastating event in Siberia would not have occurred without human-caused climate change, says Stendel. “If we assume for a moment that we don’t have any climate change,” there is a 1 in 100,000 chance of such a hot May in the region, he says. “It’s virtually impossible.”
In addition, according to Stendel, Siberian temperatures over the six-month period from December 2019 to May 2020 have also been “exceptional.” According to the Copernicus Climate Change Service, these temperatures have been the warmest recorded since 1979 and are likely to be unprecedented in the last 140 years.
This particular high temperature probably isn’t unique within the rapidly warming Arctic.
“We don’t have a whole lot of stations [in the region],” says Randall Cerveny, a meteorologist at Arizona State University in Tempe. “There are large portions that we are not monitoring. It is possible that there are higher temperatures in places [where] we don’t have instruments.”
Also, officially acknowledging this record is a way to mark a more symbolic milestone for the entire region. The World Meteorological Organization, which maintains global records of extreme weather conditions, hasn’t previously maintained a clear category of extremes for the Arctic. The addition of this temperature record, which still needs to be confirmed, would also mean the development of such a dedicated category.
The time is right for this category, Cerveny notes, because climate change is warming the Arctic twice as quickly as the rest of the world. “Given that the Arctic is one of our more climatically sensitive regions, it’s pretty important.” Verifying this record and establishing this category is not a fast process; it could take months to a few years, adds Cerveny, who investigates and confirmes the WMO’s global weather records. The development of such an Arctic temperature category requires not only the approval of WMO officials but also the collection and verification of data from eight different countries within the Arctic Circle. Even so, he says, “Everybody at different levels seems amenable to doing it.”
But as far as the temperature record itself is involved, scientists will first collect data from the Verkhoyansk station while also ensuring that it has been obtained in compliance with WMO standardized procedures. This will then be reviewed by an international panel of scientists. These processes may be further delayed as a result of the COVID-19 pandemic, says Cerveny.
Loss of ice is creating a positive warming feedback.
Accelerated warming in the Arctic region, known as the Arctic amplification, is partly related to the “positive feedback” effects that contribute to the warming already underway. The biggest effect of these warming reactions is the loss of ice, both on land and in the ocean, says Stendel. Bright snow and ice reflect most of the incoming radiation from the sun. However, the rocks or water underneath them are much darker and retain much of the heat of the sun instead of reflecting it out into space.
As melting leaves more and more rocks and the water is exposed, more solar radiation is absorbed within the area, causing temperatures to rise. “It’s a kind of vicious circle,” Stendel says.
The Siberian heat, and thawing permafrost, may be linked to a recent oil spill.
May is normally a winter month above the Arctic Circle, says Stendel. However, with the warm temperatures in Siberia continuing through the winter and spring of 2020, the snow cover melted much earlier than it would have otherwise. With the snow gone, the land is free to draw more heat from the sun.
The Arctic Circle ‘s frozen soil is called permafrost. Usually, the top meter or so of the permafrost, called the “active layer,” typically thaws in the summer. But with temperatures so high that the mushy, thawing layer expands deeper, making the ground surface more fragile. That’s a problem for buildings and facilities drilled in the permafrost, Stendel adds.
The instability may be accountable for the oil spill on 29 May near the Russian city of Norilsk, which leaked about 21,000 metric tons of oil into the Ambarnaya River and contaminated an area of around 180,000 square meters. With the melting snow disappearing earlier in the spring, the soil can also dry out earlier and more thoroughly than it would otherwise. The combination of extra heat and dry soil is “an explanation for the many fires we’ve seen” in the Arctic, Stendel says.