Now, a brand-new study published in Science and led by Adrià Descals and Josep Peñuelas, both researchers from the Spanish Council for Scientific Research (CSIC) and from CREAF, reveals that the boost in temperature is driving a rapid boost in fires in the Arctic. David Gaveau, fire professional at TheTreeMap, as well as scientists from the Desertification Research Centre (CSIC-University of Valencia), Wageningen University (Netherlands), the University of Kyoto, and the Center for International Forestry Research (CIFOR) in Indonesia, likewise took part in the research study.
” We found fires above the 72nd parallel north, more than 600 km north of the Arctic Circle, where fires are uncommon and where winter ice was still noticeable at the time of burning,” explains Adrià Descals. “Many fires were detected with a few days of difference, so we assume that increases in thunderstorms and lightning are the main cause of the fires, although additional investigations would be needed to demonstrate how much human activities may affect the fire season in this remote area.”
Rising air temperature and fire risk
Some aspects that can worsen fire risk have increased significantly, and all these elements relate to increasing temperature levels. The research study explains that aspects such as drier weather, longer summer seasons, and more plants have revealed a constant trend over the previous four years.
The Siberian Arctic experienced an uncommon number of fires in 2019 and 2020. Fires damage the permafrost and contribute to the release of carbon emissions in the kind of greenhouse gases.
A 30-kilometer-wide wildfire front spotted in the Siberian Arctic at a latitude of 69.31 ° N on August 6, 2020. Sentinel-2 Infrared color image. Credit: Adrià Descals
Referral: “Unprecedented fire activity above the Arctic Circle linked to increasing temperature levels” by Adrià Descals, David L. A. Gaveau, Aleixandre Verger, Douglas Sheil, Daisuke Naito and Josep Peñuelas, 3 November 2022, Science.
DOI: 10.1126/ science.abn9768.
” The truth that there is more and earlier greenery reduces the accessibility of water in the soil, and plants suffer higher water tension,” says Aleixandre Verger, a scientist at CSIC and CREAF.
Our work suggests that the Arctic is currently experiencing a change in fire regimes brought on by climate warming. “The locations burned in 2019 and 2020 could be remarkable occasions, but recent temperature level patterns and projected scenarios suggest that, by the end of the century, large fires such as those in 2019 and 2020 will be frequent if temperatures continue to increase at the existing rate,” conclude Adrià Descals and Josep Peñuelas.
The authors keep in mind that “the 2020 average summertime temperature– which was 11.35 degrees– will be very common from the second half of the century on if the Arctic warming continues at the very same rate.” As Adrià Descals alerts, “these temperature level anomalies increase fire risk factors, so the conditions that were resulted in the 2019 and 2020 fires will be recurrent in the Arctic by the end of the century.”
An explanatory design that links the aspects of fire
In 2019 and 2020, fire rates in the Siberian Arctic surpassed those of the last 4 years. Just in 2020, there were seven times more fires than the average because 1982 and they damaged an extraordinary location of peatlands. Josep Peñuelas explains that “the concatenation of these factors is what produced the fire rate boost.”
The summer of 2020 was the warmest in 4 years, and the large area burned in between 2019 and 2020 was unmatched, the authors explain. Around 4.7 million hectares burned in between 2019 and 2020, leading to overall emissions of 412.7 million tonnes of CO2 equivalent.
” Higher temperatures explain the earlier thaw, which in turn enables greater vegetation development and increases fuel accessibility.”
In 2019 and 2020, fire rates in the Siberian Arctic exceeded those of the last 4 years. Only in 2020, there were 7 times more fires than the average given that 1982 and they harmed an extraordinary location of peatlands. Josep Peñuelas describes that “the concatenation of these elements is what generated the fire rate increase.”
” In 2020 alone,” describes Adrià Descals, first author, “423 fires were discovered in the Siberian Arctic, which burned around 3 million hectares (an area almost as big as the whole Belgium) and caused the emission of 256 million tonnes of CO2 equivalent,” which resembles the annual emissions of CO2 in Spain. The researcher adds that “with future warming, these megafires will be frequent at the end of the century and will have various ramifications, both for the Arctic and for the worldwide environment.”
Analysis of four years of satellite observations
The authors measured, from satellite observations from 1982 to 2020, the area burned in Siberia above the Arctic Circle, a region covering 286 million hectares. “While the observations indicated that the 2020 fire season was extraordinary, no exact quantitative assessment had been made so far in this remote area,” states co-author David Gaveau.
On the other hand, heatwaves and, above all, the increase in surface temperature level, can increase convective storms and lightning, which have been very rare so far in the Arctic, but “they are expected to increase as the climate warms,” state the researchers..
In turn, “severe heat waves, such as in 2020 in the Siberian Arctic, increase vulnerability to drought, as they can desiccate plants and lower peat moisture, and therefore increase the intensity of fires and carbon emissions.”
The concern that stayed unanswered was whether this increase in fires in 2019-2020 was an exceptional case or a pattern that will get even worse as the Arctic warms.
” Climate warming therefore has a double effect on fire threat: it increases the vulnerability of plants and peatlands to fire and, on the other hand, it increases the variety of ignitions triggered by thunderstorms,” describes Adrià Descals.
The Siberian Arctic experienced an unusual variety of fires in 2019 and 2020. This raised issues in the clinical community, as the Arctic has large areas of permafrost, a completely frozen layer of subsoil that accumulates large amounts of carbon. Fires damage the permafrost and contribute to the release of carbon emissions in the form of greenhouse gases.
In this work, the researchers show that fire danger factors connected with temperature level have increased in recent decades and that there is an exponential relationship in between the degree burned every year and these factors. “Temperatures are reaching a critical limit where little boosts above the summertime average of 10 ° C can exponentially increase the area burned and the associated emissions,” discusses Josep Peñuelas.
