Arctic tundra now emitting more carbon than it absorbs, NOAA report reveals

By Elías Thorsson December 11, 2024
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NOAA’s Barrow Observatory in Utqiagvik, Alaska, looks out over tundra. (Yereth Rosen)

The Arctic tundra, long considered a critical carbon sink, has become a net source of carbon dioxide emissions, according to the National Oceanic and Atmospheric Administration’s (NOAA) 2024 Arctic Report Card. This alarming shift is attributed to rising temperatures, increased wildfire activity and the accelerated thawing of permafrost.

Scientists have found that warming in the Arctic is occurring at a rate four times faster than the global average, leading to significant ecological changes. Thawing permafrost is exposing ancient organic material that, when decomposed, releases large amounts of greenhouse gases such as carbon dioxide and methane into the atmosphere. In addition, more frequent and intense wildfires in permafrost regions are exacerbating carbon emissions, further fueling global warming.

“Our observations now show that the Arctic tundra, which is experiencing warming and increased wildfire activity, is emitting more carbon than it stores, which will worsen climate change impacts,” NOAA Administrator Rick Spinrad said in a statement.

This shift in the tundra’s role from a carbon sink to a carbon can have wide ranging implications far beyond the Arctic. The release of greenhouse gases from the region is expected to intensify warming across the planet, creating a feedback loop that accelerates permafrost degradation and further emissions.

Other notable findings from the 2024 Arctic Report Card:

  • Arctic annual surface air temperatures ranked second-warmest since 1900.
  • An early August 2024 heatwave set all-time record daily temperatures in several northern Alaska and Canada communities.
  • The last nine years are the nine warmest on record in the Arctic.
  • All 18 of the lowest September minimum ice extents have occurred in the last 18 years.
  • When including the impact of increased wildfire activity, the Arctic tundra region has shifted from storing carbon in the soil to becoming a carbon source to the atmosphere. Circumpolar wildfire emissions have averaged 207 million tons of carbon per year since 2003.
  • Greenland Ice Sheet mass loss was the lowest since 2013.