Scientists studying Alaska’s thawing permafrost have found a carbon feedback loop that climate policy models have systematically underestimated. It could add nearly half a degree of warming by the end of the century, regardless of the emissions reductions Europe pursues.
The difference between what policymakers thought they were addressing and what’s actually happening matters. The United Nations estimates that, without policy changes, the world will warm 2.6 degrees Celsius above pre-industrial levels by the end of the century. That figure excludes a few tenths of a degree from permafrost thaw, according to Sue Natali of the Woodwell Climate Research Center and Gustaf Hugelius, a permafrost expert at Stockholm University.
Two recent studies put the added warming from Arctic methane and carbon dioxide emissions at about a quarter degree Celsius. Scientists said that contribution would warm Earth about as much as a major industrialized country such as the United States or the whole of Europe. The finding raises questions about how Europe sets its climate ambitions and whether current decarbonization targets remain sufficient.
The Scale of the Carbon Trap
Permafrost, ground that stays frozen below 32 degrees Fahrenheit for at least two years, holds three times as much carbon as the atmosphere currently contains, according to Ted Schuur, an ecologist at Northern Arizona University. The Arctic is warming four times faster than the rest of the globe. As the ground thaws, plants and animals that have decomposed for thousands of years begin breaking down into methane and carbon dioxide.
“Once you start leaking this carbon out, there’s so much in the ground that it’s not going to shut off,” Schuur said. He called the process one of climate change’s “scary tipping points.” “Essentially every year is setting a permafrost record.”
For millennia, the Arctic served as a carbon sink: plants pulled heat-trapping gas from the air and stored it in frozen ground. A few years ago, warming shifted that balance, according to Duncan Menge, a Columbia University ecologist. Thawing ground now releases more heat-trapping gases than it absorbs. In a September study co-authored by Natali, researchers found that permafrost thaw and other warming-driven emissions from fires and changes to wetlands and lakes are likely to increase warming by 20 percent by the end of the century.
Andrew Weaver, a University of Victoria climate scientist who first calculated the half-degree of expected permafrost warming 14 years ago, said the amount may be small and not a “scenario of doom.” But it’s something “that we’re going to have to deal with” on top of other warming.
Infrastructure Vulnerability in Arctic Regions
Thawing ground destabilizes the land itself. Once-solid ground collapses and sinks. Permafrost has long supported homes, roads, and pipelines in Alaska and other Arctic regions, but it’s becoming less reliable. Scientists recently saw a crater-like hole 10 feet deep in Galbraith on Alaska’s North Slope. These depressions, known as slumps, form when ice melts and land collapses, releasing methane. A Woodwell team has identified more than 40,000 slumps across the Arctic using satellites, according to scientist Kyle Arndt.
Photographs from 1 year ago show thawing permafrost warping a road in Kotzebue, Alaska. Photographs dated 2 years ago show coastal permafrost melting in Newtok, Alaska. Vladimir Romanovsky, a University of Alaska Fairbanks geophysicist, recalled that when he began studying permafrost in the 1970s, “everybody believed permafrost was very stable. People thought it was forever.” He said that’s no longer the case.
“It took some thousands and tens of thousands of years to sequester this carbon into permafrost,” Romanovsky said. “You need a new ice age to put back this ice into the ground.”
The Policy Integration Problem
Natali and Hugelius have pointed to a major gap: political and scientific estimates of future warming usually leave out the additional greenhouse gases released by thawing permafrost. That omission matters for Europe’s climate strategy. If the baseline warming projections behind the European Green Deal and net-zero commitments excluded a quarter degree of permafrost-driven warming, then policymakers may have calibrated their response using an incomplete picture.
Robert Rohde, a Berkeley Earth climate scientist, noted that flooding in Nepal killed more than 1,000 people after part of a glacier collapsed following a heat wave. Dmitry Streletskiy, a George Washington University permafrost scientist and lead author of an August study that found significant thawing across most of the Northern Hemisphere, said weakened frozen ground was likely one of several factors in the Nepal disaster.
Natali described visiting a research tunnel the U.S. Army drilled under a Fairbanks hill. Its icy walls preserve bison and mammoth bones; the tunnel is artificially cooled and used for training. “Every time I go there, I’m reminded of the magnitude of the problem. You smell it. You see it. You feel it all around you,” she said. “This isn’t a problem of 100 years from now. This is a problem of right now.”
Why This Matters:
Europe’s climate policy architecture rests on warming projections that now appear incomplete. If permafrost thaw adds another quarter degree of warming—equivalent to the warming impact of an entire continent—then current decarbonization targets may need recalibration. Or member states must recognize that even successful emissions cuts may not deliver the promised temperature stabilization. The challenge has two parts: climate policy credibility depends on transparent baseline assumptions, while Arctic infrastructure, particularly in Nordic countries, needs adaptive planning for accelerating permafrost degradation. The gap between modeled and actual warming also shows why climate strategy can’t rely on European action alone: Arctic processes operate at planetary scale and require international coordination beyond the EU’s regulatory reach.