After locking carbon dioxide in its frozen soil for millennia, the Arctic tundra is undergoing a dramatic transformation, driven by frequent wildfires that are turning it into a source of carbon dioxide emissions, a US agency said on Tuesday.
This profound change was detailed in the National Oceanic and Atmospheric Administration’s 2024 Arctic Report Card, which showed that the annual surface temperature in the Arctic this year was the second-warmest on record since 1900.
“What we’re seeing now is that the Arctic tundra, which is warming and increasing wildfires, is releasing more carbon than it’s storing, which will exacerbate climate change,” said NOAA Administrator Rick Spinrad.
Findings are based on an average of observations from 2001-2020.
Climate warming has two effects on the Arctic. While it encourages plant reproduction and growth, which removes carbon dioxide from the atmosphere, it also leads to increased surface air temperatures that cause permafrost to melt.
Thawing permafrost releases carbon previously locked in the frozen soil as carbon dioxide and methane — two powerful greenhouse gases — through microbial decomposition.
In 2024, Alaska recorded its second-warmest permafrost temperature on record, the report said.
Human-induced climate change is also increasing the frequency of wildfires, which have increased in burned area, intensity, and carbon emissions.
The heart of the forest not only burns vegetation and soil organic matter, releasing carbon into the atmosphere, but also removes protective soil layers, accelerating long-term permafrost thaw and associated carbon emissions.
Since 2003, circumpolar wildfire emissions have added 207 million tons of carbon annually, according to NOAA. At the same time, Arctic terrestrial ecosystems continued to contain methane.
“Last year, 2023, was the largest fire year on record for Canadian wildfires, burning more than twice as often as any other year in Canada,” report author Brendan Rogers said at a press conference.
The fire released 400 million tonnes of carbon — more than two and a half times the emissions from all other sectors in Canada combined, he added.
Meanwhile, 2024 ranks as the second-highest year for wildfires in the Arctic Circle.
– ‘Terrible way’ –
Asked whether the Arctic’s shift from carbon sink to source would be permanent, Rogers said it remains an open question. While boreal forests in the south still serve as carbon sinks, northern areas are more vulnerable.
“Of course there is a difference between the year,” he stressed. “What I’m talking about here is the average situation we’ve seen over the past 20 years.”
Speaking to the media, Brenda Ekwurzel, climate expert at the Union of Concerned Scientists said “the climate crisis we are seeing in the Arctic is already having consequences for communities around the world.”
“The alarming forecast for carbon emissions in the near future does not bode well. Once there, many of these impacts on ecosystems cannot be reversed.”
As well as warming, the Arctic is getting wetter, with summer 2024 seeing the most precipitation on record.
The event accelerates coastal erosion, threatening Indigenous communities that rely on stable ice and traditional hunting practices.
Warmer temperatures are affecting wildlife too, with reports finding tundra caribou numbers have declined by 65 percent in the past 20 to three years — with hot summers affecting their habitats and survival, as well as changes in winter and winter.
Surprisingly, however, Alaska’s ice seal population remains healthy.
The report found no long-term effects on body condition, developmental age, pregnancy rate, or offspring survival of four species of ice floes — ringed, bearded, spotted, and ribbon — that live in the Bering, Chukchi, and Beaufort. the seas.
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