After the Amazon, this key biome in the Arctic also becomes a net emitter. Global warming and the increase in wildfires degrade the permafrost, causing the overall emissions balance to shift.
The Arctic tundra has become a net emitter, releasing more carbon dioxide than it absorbs. It is the second major region of the planet, after the Amazon, to lose its crucial role as a carbon sink.
“Our observations now show that the Arctic tundra, which is experiencing warming and an increase in wildfires, is emitting more carbon than it stores, which will worsen the impacts of climate change,” said Rick Spinrad of NOAA, the U.S. National Oceanic and Atmospheric Administration. The agency has just released its 2024 Arctic Report Card.
“This is another signal, predicted by scientists, of the consequences of inadequate reduction of fossil fuel pollution,” added the NOAA scientist.
How is the Arctic tundra changing with global warming?
According to the U.S. agency, the increase in CO2 emissions from the Arctic tundra and its shift to a net emitter is mainly due to wildfires and global warming.
Arctic wildfires have released an average of 207 million tons of carbon annually since 2003, accelerating the degradation of permafrost and increasing emissions of CO2 and methane, another important greenhouse gas with climate-altering effects 82.5 times greater than CO2 in the first 20 years it is present in the atmosphere.
The primary driver behind these fires is global warming. The Arctic is warming four times faster than the global average, contributing to the release of greenhouse gases trapped in the permafrost and worsening the impacts of climate change. In 2023, annual surface temperatures in the Arctic were the second hottest ever recorded since 1900.
Additionally, 2024 saw the rainiest summer on record, along with a reduction in the length of the snow season, despite above-average snowfall in 2023-2024.
“Many of the vital signs of the Arctic we monitor are reaching or nearing record highs or lows almost every year,” said Gerald Frost, an Alaska Biological Research scientist and one of the authors of the NOAA report. “This is an indication that the extreme recent years are the result of persistent long-term changes, not the result of natural climate variability.”
