Permafrost Thaw Amplifies Global Warming and Triggers Local Hazards

Permafrost—ground that remains frozen year-round across Siberia, Canada, Alaska and parts of Europe—is thawing faster as the planet warms. The thaw releases stored carbon as carbon dioxide (CO2) and methane (CH4), creating a feedback on the climate system. Melting ice that once cemented mountain slopes is destabilising terrain, exemplified by the heightened landslide risk above the Swiss village of Kandersteg.

The Guardian

The permafrost region spans roughly 20 million sq km and stores 1,500 gigatons of carbon, three times the carbon in all living vegetation. When it thaws, microbes decompose ancient plant material, emitting CO2 and, in water-logged conditions, CH4. The process can become irreversible locally, forming thermokarst lakes, wetlands or river gullies that alter soil thermal conductivity and snow cover.

The Guardian

• Projected loss of 200–300 gigatons of CO2-equivalents if warming reaches 1.8 °C–3.6 °C by the end of the century.

The Guardian

• Each degree of warming avoided could preserve 4 million sq km of permafrost.

The Guardian

• Arctic warming is up to four times the global mean, accelerating carbon release and terrain instability.

The Guardian

A University of New Mexico field campaign in July surveyed the Kuparuk, Atigun and Sagavanirktok River watersheds on Alaska’s North Slope. Researchers collected soil cores, pore-water, and stream samples to assess how deeper active layers affect groundwater chemistry and carbon transport. The team is building a reactive-transport model to simulate future hydrologic and chemical changes under warming scenarios.

UNM researchers study permafrost thaw, water quality and carbon cycling in Alaska

The Spitze Stein mountain formation above Kandersteg (?1,300 residents) is losing permafrost-derived ice that once acted as cement, raising the probability of a massive landslide. Professor Markus Stoffel, University of Geneva, links the rising risk directly to increasing temperatures. Residents Brigitte Jüni and Rudolf Isler note that falling rocks have been observed for years and that authorities have taken precautionary measures, but they stress that the underlying driver is climate-induced permafrost loss.

Permafrost thaw threatens a rockslide above a Swiss village

• Marisa Repasch, assistant professor at the University of New Mexico, emphasizes that “the main goal of our recent field campaign in Alaska was to investigate how permafrost thaw may be impacting surface and groundwater quality in Arctic watersheds.”

UNM researchers study permafrost thaw, water quality and carbon cycling in Alaska

• “Frozen ground prevents infiltration, causing the soils to become saturated with water from snowmelt and rain,” — Marisa Repasch

UNM researchers study permafrost thaw, water quality and carbon cycling in Alaska

• “Because the Arctic is warming rapidly, these watersheds provide natural laboratories for observing how permafrost thaw and changing hydrology alter surface processes and their role in the global carbon cycle,” — Marisa Repasch

UNM researchers study permafrost thaw, water quality and carbon cycling in Alaska

Scientific estimates differ on the proportion of carbon released as methane versus carbon dioxide. The precise timing of regional tipping points remains uncertain, with models unable to predict which permafrost patches will become wet versus dry.

The Guardian

• Continued monitoring of Arctic watersheds and mountain slopes will refine models of carbon release and landslide risk.

UNM researchers study permafrost thaw, water quality and carbon cycling in Alaska

• Expanded field campaigns and interdisciplinary collaborations aim to improve predictions of water-quality changes and ecosystem responses.

UNM researchers study permafrost thaw, water quality and carbon cycling in Alaska