Global warming is causing an increase in wildfires in Arctic Siberia and threatens to release huge amounts of carbon into the atmosphere in the coming decades, warns a new study published in Science on Thursday.

Researchers fear that a threshold will soon be reached at which a small increase in temperature will cause wildfires in the region to grow exponentially.

According to a study published in the journal Science, in just two years, 2019 and 2020, fires in this remote part of the world destroyed almost half of the area burned in the previous 40 years.

According to researchers, they released about 150 million tons of carbon into the atmosphere, contributing to global warming in a closed circle.

The Arctic, located above the Arctic Circle, is warming four times faster than the rest of the planet. “It is this increased climate that is driving the anomalous fire activity,” David Gavo, one of the study’s authors, told AFP.

The researchers focused on an area five and a half times the size of France, using satellite images to track the areas burned each year between 1982 and 2020.

According to researchers, more than 2.5 million hectares were destroyed by the flames in 2020, emitting the equivalent amount of CO2 that Spain emits in a year.

That year, the Siberian summer was on average three times warmer than in 1980. In the Russian city of Verkhoyansk, 38°C was recorded in June, a record for the Arctic region.

The average summer air temperature (from June to August) exceeded 10°C only four times during the study period: in 2001, then in 2018, 2019 and 2020. These were the four years with the highest number of fires.

Researchers fear that this 10°C threshold marks a “tipping point” that will be crossed with increasing frequency, explained David Gavo. “The system goes crazy and with a little increase above 10°C suddenly there are a lot of fires.”

Thawing of permafrost

These areas in Siberia, Russia, are mostly peatlands, swampy areas that can be covered by tundra and absorb carbon. Fires release it into the atmosphere in the form of CO2.

Fires also damage permafrost, which releases more carbon into the atmosphere, some of which remains trapped in the ice for centuries or even millennia.

“If there are fires every year, the condition of the soil is going to get worse and worse, so there will be more and more emissions from these soils, and that’s a concern,” says Gavo.

The amount of CO2 emissions in 2020 was “large” but “could be much more catastrophic than in the future”, warns a researcher whose company The Tree map studies deforestation and wildfires.

Rising temperatures affect the climate in several ways: More water vapor rises into the atmosphere, causing more storms and therefore more lightning that ignites fires. Vegetation grows larger, providing more fuel, but loses more water, resulting in desiccation.

Different scenarios

For the future, the study analyzed two possible scenarios.

In the first scenario, nothing is done about climate change and temperatures continue to rise steadily. In this case, fires of the same scale as in 2020 are possible every year.

Under the second scenario, greenhouse gas concentrations stabilize and temperatures reach a plateau by the second half of the century.

Then, fires like the one in 2020 would occur “on average every 10 years,” study lead author Adria Descals Ferrando told AFP.

In any case, “fire summers like the one in 2020 will become more and more frequent from 2050,” summarized David Gavo.

With the UN climate conference COP27 just days away, a researcher hopes world leaders can agree on progress.

“The most important thing is to stop using fossil fuels that emit CO2,” he says, because “one day we will reach a point where the planet will be uninhabitable for most of us.

On the same topic:

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• Europe’s climate is warming twice as fast as the world average / What will be the consequences