Permafrost thaw: sinking houses releasing methane and the climate feedback loop

01What permafrost is and why it is thawing

Permafrost is ground that stays frozen for at least two consecutive years. It underlies roughly a quarter of the Northern Hemisphere, concentrated across Siberia, Alaska, northern Canada, and the Tibetan Plateau. Some of it has been frozen since the last ice age, holding organic matter that has been locked away from decomposition for tens of thousands of years.

Thawing is driven by rising Arctic temperatures, which are warming up to four times faster than the global average. When air and ground temperatures climb above freezing, the ice that binds permafrost soil melts. The ground subsides, water pools on the surface, and the previously frozen organic material begins to decompose, releasing carbon dioxide and methane into the atmosphere.

02How thawing permafrost damages infrastructure

Buildings, roads, pipelines, and airports across the Arctic were constructed assuming the ground beneath them would stay frozen. As permafrost thaws, the ground loses its structural integrity. Foundations crack, walls split, and roads buckle. In Russia alone, thousands of apartment blocks, industrial facilities, and sections of the Trans-Siberian Railway are at risk.

In Alaska, entire villages are being relocated because the land beneath them is collapsing. The community of Newtok has been moving to a new site for years. The damage is not gradual in all places: sudden thaw events can drop the ground by several feet in a single season, snapping pipes and shearing buildings off their foundations.

03The methane and CO2 release feedback loop

When permafrost thaws, microbes decompose the newly available organic matter. In dry, oxygen-rich conditions, the decomposition produces carbon dioxide. In waterlogged, oxygen-poor conditions, it produces methane, a greenhouse gas roughly 80 times more potent than CO2 over a 20-year period.

The released greenhouse gases warm the atmosphere, which in turn accelerates permafrost thaw. This is a classic climate feedback loop. The concern is not that permafrost will release all its carbon at once, but that the thaw is self-reinforcing: more warming drives more thaw, which drives more emissions, which drive more warming.

04Which regions are most affected

Siberia holds the largest permafrost carbon reserves, particularly in the Yedoma region, where ice-rich sediments store exceptionally dense organic matter. Alaska and northern Canada also have extensive permafrost, and both are seeing accelerated ground temperature increases. The Tibetan Plateau, sometimes called the Third Pole, is warming rapidly and contains high-altitude permafrost that is vulnerable to degradation.

Scandinavia and parts of northern Europe have discontinuous permafrost that is already fragmented and thawing. The rate of change varies by region depending on ground ice content, soil type, vegetation cover, and local climate trends, but the direction is consistent: everywhere, permafrost is warming.

05The scale of the carbon stored in permafrost

The Northern permafrost region holds an estimated 1,400 to 1,600 gigatonnes of organic carbon. For comparison, the atmosphere currently contains about 850 gigatonnes of carbon. Even if only a fraction of the permafrost carbon decomposes and reaches the atmosphere, it would add significantly to atmospheric CO2 concentrations.

Not all of this carbon will be released. Much depends on how deep and how fast the thaw progresses, and whether the decomposition happens in dry or wet conditions. But the sheer scale of the reservoir means that permafrost is one of the largest potential sources of additional greenhouse gas emissions on the planet.

06How permafrost thaw accelerates climate change

Permafrost thaw is not currently included as a distinct emissions source in most climate models, which means model projections may underestimate future warming. The Intergovernmental Panel on Climate Change acknowledges this as a source of uncertainty. The risk is what scientists call a tipping point: a threshold beyond which the feedback loop becomes self-sustaining regardless of human emissions reductions.

Research published in recent years has revised upward the expected rate of permafrost carbon release. Even under moderate warming scenarios, models now project that permafrost could add tens of gigatonnes of carbon to the atmosphere by mid-century. Under high-emissions scenarios, the figure could be much larger, and the Arctic would shift from a carbon sink to a net source.

07What can be done about it

The single most effective response to permafrost thaw is reducing global greenhouse gas emissions to limit warming. The less the planet warms, the less permafrost thaws, and the less carbon is released. There is no technological fix that can refreeze permafrost at scale.

At the local level, communities are adapting by redesigning infrastructure to accommodate ground movement, elevating buildings on adjustable pilings, and relocating settlements where the land is no longer viable. Monitoring networks are being expanded to track ground temperatures and emission rates. But these are adaptation measures, not solutions to the underlying cause of the thaw.