A recent study published in Nature Communications suggests that melting glaciers in Svalbard, an Arctic archipelago north of Norway, may be releasing ancient methane trapped in rocks beneath the ice. Led by Gabrielle Kleber of the iC3 Polar Research Hub in Tromsø, Norway, the research analyzed 148 water samples from 19 glacier-fed rivers in central Svalbard. This is the most comprehensive study to date on methane levels in meltwater from glaciers in the region. Some samples showed methane concentrations up to 425 times higher than the background level found in the atmosphere. The study found that the methane is likely coming from geological sources, not from microbes living under the ice, as seen in Greenland. This methane is thought to originate from ancient shale layers rich in organic carbon. Over millions of years, these layers have transformed into methane and other gases. The presence of related gases like ethane and propane in some samples supports this conclusion. The physical condition of the glacier bed plays a key role in how much methane is released. Glaciers with thawed, wet beds were more effective at transporting methane to the surface, while those frozen to their beds were less connected to the underlying rocks, even when methane-rich geology was present. Researchers used ground-penetrating radar and ice surveys to map the conditions of the glacier beds and estimate how much of each bed was thawed and able to carry water. The study estimates that land-terminating glaciers in Svalbard could transport between 182 to 368 tonnes of methane annually through meltwater. This adds to previous estimates of methane from groundwater springs in front of glaciers. The findings suggest that this process is a widespread, yet undercounted, way that ancient carbon is reaching the atmosphere. Methane is a potent greenhouse gas, though the amounts reported in this study are much smaller than human-caused emissions from fossil fuels, agriculture, and waste. Still, the study highlights a natural feedback loop that could intensify as the Arctic warms. As glaciers thin and retreat, more meltwater may reach their beds, increasing contact with rocks and groundwater, potentially releasing more methane. However, some glaciers may become colder at their bases as they shrink, which could reduce the release of methane through subglacial rivers. This research builds on earlier work by Kleber and co-author Leonard Magerl, who previously found that meltwater from a Svalbard glacier could carry significant amounts of methane from beneath the ice. New groundwater springs in the area are also releasing methane, showing that Svalbard has multiple, understudied sources of this powerful greenhouse gas.