The Arctic holds vast reserves of methane trapped in underground deposits, sealed beneath a frozen permafrost layer and under glaciers. This methane has long contributed to the greenhouse gas mix, its warming potential higher than carbon dioxide. It has persisted in the air at lesser levels for decades, but in places beneath ice and permafrost, its containment has shielded the climate from larger releases.
When pressures and temperatures rise enough, methane under permafrost and glaciers can form solid gas hydrates. Climate warming and glacier retreat change these conditions, potentially destabilizing hydrates and allowing methane to escape from subsurface stores into the polar atmosphere.
Researchers from the University of Cambridge in the United Kingdom and the Svalbard University Center in Norway have identified substantial methane emissions emerging directly from warming glaciers in the Arctic.
Arctic melting releases methane trapped in ice—an image that underscores the fragile balance of polar systems.
The study, published in Nature Geoscience, suggests that methane emissions will likely grow as Arctic glaciers melt, adding to global warming through a feedback loop linked to ice loss. A lead author from Cambridge, Gabrielle Kleber, notes that these sources are a significant and growing part of the methane budget that global estimates have often missed.
Kleber spent nearly three years tracing the water chemistry of more than a hundred springs in Svalbard, where air temperatures rise twice as fast as the Arctic average. As warming continues, scientists can preview the potential scale of methane release in this region.
An unknown methane emission route
Professor Andrew Hodson from the University Center of Svalbard explained that Svalbard sits at the frontline of Arctic climate change. He emphasizes the importance of understanding methane removal near receding glaciers and acknowledges that this new evidence points to additional pathways for methane escape beyond the more commonly studied permafrost.
A second author from Cambridge, Alexandra Turchyn of the Department of Earth Sciences, Cambridge, notes that attention often centers on permafrost, but the new findings reveal that methane can originate from glacier-adjacent sources as well. This expands the global methane budget and highlights the need to integrate glacier-associated emissions into climate models.
The methane release appears to originate from a gallery system of springs fed by a network of groundwater in underlying sediments and bedrock. Much of this system lies beneath ice, ready to surface as glaciers retreat and expose subterranean water to the surface.
2,000 tons of methane a year in Svalbard alone
As glaciers retreat, springs appear where groundwater networks intersect with the surface. Experts have found that methane emissions in Svalbard can exceed 2,000 tons annually, accounting for roughly 10 percent of Norway’s total methane from oil and gas activities. Kleber warns that this source could grow more significant if global warming continues unchecked. These emissions are not always easy to spot, prompting Kleber to learn to recognize patterns from satellite imagery.
In Svalbard, the research team mapped land areas formed by glacier retreat and marked blue dots that indicated groundwater seepage reaching the surface. They traveled by snowmobile to collect groundwater samples and analyze water chemistry. The results showed high concentrations of dissolved methane at every site, meaning that when spring water surfaces, extra methane can escape into the atmosphere.
The localized emission points correlated with the rock type—rock formations such as shale and coal harbor natural gases, including methane produced by the breakdown of organic matter during rock formation. Methane can migrate upward through surface cracks into groundwater. Hodson notes that understanding glacier melt in Svalbard is still evolving, and more consequences are likely to emerge as glaciers continue to disappear.
The overall amount of methane escaping from these sources is expected to rise as the trapped gas under glaciers becomes exposed. This underscores the urgent need to assess the risk of a methane surge as glacier retreat persists. A synthesis of the study highlights the growing importance of glacier-associated methane in the global budget, inviting further research and monitoring across polar regions.
This work adds to the broader picture of Arctic methane emissions, emphasizing that the cryosphere stores a more complex and interconnected methane system than previously understood. The study points to multiple pathways by which methane can reach the atmosphere, including groundwater-driven vents and gas-bearing rocks in glaciated landscapes. As climate trends continue, these pathways may intensify, contributing to a layered and evolving Arctic methane story.
Endnotes: The findings are reported in Nature Geoscience and are part of ongoing investigations into Arctic methane sources and their implications for climate projections.