Climate change is already a runaway monster feeding itself. In the Russian city of Verkhoyansk in Siberia, they were so used to the cold that children stopped going to school only when the temperature dropped below 50 degrees below zero. However, an unusual heat wave caused a temperature of 38 degrees on June 20, 2020. The icy spot where Stalin’s Gulag once stood looked like a Mediterranean beach in summer. It was the hottest temperature ever recorded north of the Arctic Circle. An international team of scientists is now revealing the exact consequences of this thermal anomaly. Ice melted everywhere and the resulting megafires in the Siberian Arctic destroyed three million hectares throughout 2020, an area similar to that of Belgium. The CO₂ emissions caused by the fire were equivalent to all of Spain in one year. Global warming causes more global warming.
The researchers, led by Spanish ecologists Josep Peñuelas and Adrià Descals, analyzed four decades of satellite data. Wildfires in the Arctic are common, but the scale of these fires in 2019 and 2020 has never been seen before. In recent summers, the satrap Vladimir Putin has had to mobilize the Russian army to fight the Siberian fire. The scientific team’s data shows that the area that burned in 2020 was seven times the average for the previous four decades. The authors found that temperature increase causes a linear increase in surface area burned, but above the 10 degree threshold the effect is “almost exponential”. Their findings will be published this Thursday in Science magazine, a flagship of the world’s best science.
A satellite image of one of the Siberian Arctic Adrià Descals (CREAF) fires studied by CREAF researchers
The Arctic is one of the regions of the planet where global warming is most felt. The temperature on Earth has risen by an average of 0.8 degrees since the late 19th century, but the increase in the Arctic is already over 2 degrees. Five of the world’s top business leaders — oil majors ExxonMobil, Royal Dutch Shell, Chevron, BP and Total — spend around €200 million a year on campaigns to gloss over their image and admit measures to reduce carbon emissions, according to a report by the British prevent organization InfluenceMap. The future is alarming. The latest forecasts from the Arctic Council assume that the average air temperature in the Arctic will rise by 3.3 to 10 degrees in 2100 compared to the average for the period 1985-2014.
Peñuelas describes a vicious circle that feeds on itself. High temperatures cause plants to use water earlier, causing the soil to dry out more. Flashes from storms ignite megafires that devastate trees, but also arctic soils dominated by peat: fossil carbon made from plant debris. Adding to the CO₂ emitted by burning forests is the gas released by burning soil carbon. And this CO₂, which is responsible for the greenhouse effect, in turn increases temperatures around the world. “We expected this to happen with the frequency and intensity it is now happening several decades from now. That doesn’t mean it will happen every year, but it is almost certain that in a few years it will become more and more common. We are very concerned,” warns Peñuelas, CSIC researcher at the Center for Ecological Research and Forest Applications in Cerdanyola del Vallès (Barcelona).
Satellite data shows that between 2019 and 2020, the fire swept about 4.7 million hectares – the area of the Dominican Republic – in the Siberian Arctic. That’s nearly half the total amount burned over the entire 1982-2020 period. Arctic fires are so devastating that they can smolder underground through the winter and flare up again the following summer. The scientific community has coined a descriptive term for these fiery undead: zombie fire.
Ecologist Josep Peñuelas in his office.CREAF
Peñuelas is one of the most influential ecologists in the world. His research has been published in leading international scientific journals. However, he is self-critical. Throwing tomato sauce or mashed potatoes at Monet and Van Gogh stained glass is not his style, but he applauds the scientists and activists fighting for society to understand the magnitude of the challenge and the urgency of solutions. “Perhaps they are doing what almost all of us who advocate for this should do: take to the streets and remind ourselves that we face a really serious problem that compels us to change the way how we use the resources of a planet that is finite, although we continue to use it as if it were unlimited,” reflects Peñuelas. “We only stopped the world because of Covid, but climate change can suffer and kill many more people than Covid, it just doesn’t happen overnight, it happens the day after tomorrow. But the day after tomorrow is not that far either,” he warns. “We need to decarbonize the activity of human society.”
The CSIC researcher emphasizes that the increase in megafires is not exclusively affecting Siberia, but is also being observed in California, Australia, Spain and other Mediterranean countries. CO₂ emissions from combustion amplify the greenhouse effect and raise temperatures, which in turn leads to more fires. “The spectacular thing about this work is seeing this phenomenon in the Arctic. We didn’t think it would happen there,” explains Peñuelas.
The Siberian Arctic occupies 70% of the entire Arctic land. US ecologists Eric Post of the University of California at Davis and Michelle Mack of Northern Arizona University warn in the journal Science that current predictions of global warming do not take into account this vicious cycle of increased temperature and increased fires in the Arctic, the greater release of CO₂ from the soil peat and, in turn, the increase in temperature due to this greenhouse effect. “The massive release of CO₂ from the Siberian fires of 2019 and 2020 shows how quickly northern ecosystems can evolve from carbon-absorbing sinks to carbon-emitting sources,” US ecologists warn.
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