Arctic Tundra Has Turned From 'Carbon Sink to Carbon Source' in Dangerous Flip: NOAA
"This is yet one more sign, predicted by scientists, of the consequences of inadequately reducing fossil fuel pollution," said one scientist.
Permafrost in the Arctic has stored carbon dioxide for millennia, but the annual Arctic Report Card released by the National Oceanic and Atmospheric Administration reveals a concerning shift linked to planetary heating and a rising number of wildfires in the icy region: The tundra is now emitting more carbon than it is storing.
The report card revealed that over the last year, the tundra's temperature rose to its second-highest level on record, causing the frozen soil to melt.
The melting of the permafrost activates microbes in the soil which decompose the trapped carbon, causing it to be released into the atmosphere as planet-heating carbon dioxide and methane.
The release of fossil fuels from the permafrost is also being caused by increased Arctic wildfires, which have emitted an average of 207 million tons of carbon per year since 2003.
"Our observations now show that the Arctic tundra, which is experiencing warming and increased wildfire, is now emitting more carbon than it stores, which will worsen climate change impacts," said Rick Spinrad, administrator of NOAA. "This is yet one more sign, predicted by scientists, of the consequences of inadequately reducing fossil fuel pollution."
Sue Natali, a scientist at the Woodwell Climate Research Center in Massachusetts and one of 97 international scientists who contributed to the Arctic Report Card, told NPR that 1.5 trillion tons of carbon are still being stored in the tundra—suggesting that the continued warming of the permafrost could make it a huge source of planet-heating greenhouse gas emissions.
Along with the "Arctic tundra transformation from carbon sink to carbon source," NOAA reported declines in caribou herds and increasing winter precipitation.
The report card showed that the autumn of 2023 and summer of 2024 saw the second- and third-warmest temperatures on record across the Arctic, and a heatwave in August 2024 set an all-time record for daily temperatures in several communities in northern Alaska and Canada.
The last nine years have been the nine warmest on record in the Arctic region.
"Many of the Arctic's vital signs that we track are either setting or flirting with record-high or record-low values nearly every year," said Gerald (J.J.) Frost, a senior scientist with Alaska Biological Research, Inc. and a veteran Arctic Report Card author. "This is an indication that recent extreme years are the result of long-term, persistent changes, and not the result of variability in the climate system."
Brenda Ekwurzel, a climate scientist at the Union of Concerned Scientists, emphasized that the continuous release of fossil fuel emissions from oil and gas extraction and other pollution has caused the Arctic to warm at a faster rate than the Earth as a whole over the past 11 years.
"These combined changes are contributing to worsening wildfires and thawing permafrost to an extent so historic that it caused the Arctic to be a net carbon source after millennia serving as a net carbon storage region," said Ekwurzel. "If this becomes a consistent trend, it will further increase climate change globally."
The Arctic Report Card was released weeks before President-elect Donald Trump is set to take office. Trump has pledged to slash climate regulations introduced by the Biden administration and to increase oil and gas production. He has mused that sea-level rise will create "more oceanfront property" and has called the climate crisis a "hoax," while his nominee for energy secretary, Chris Wright, the CEO of the fracking company Liberty Energy, has claimed that climate warming is good for the planet.
"These sobering impacts in the Arctic are one more manifestation of how policymakers in the United States and around the world are continuing to prioritize the profits of fossil fuel polluters over the well-being of people and the planet and putting the goals of the Paris climate agreement in peril," said Ekwurzel. "All countries, but especially wealthy, high-emitting nations, need to drastically reduce heat-trapping emissions at a rapid pace in accord with the latest science and aid in efforts of climate-vulnerable communities to prepare for what's to come and help lower-resourced countries working to decrease emissions too."
