Welcome to DU!
The truly grassroots left-of-center political community where regular people, not algorithms, drive the discussions and set the standards.
Join the community:
Create a free account
Support DU (and get rid of ads!):
Become a Star Member
Latest Breaking News
Editorials & Other Articles
General Discussion
The DU Lounge
All Forums
Issue Forums
Culture Forums
Alliance Forums
Region Forums
Support Forums
Help & Search
Svalbard winter warming is reaching melting point
Comment | Open access | Published: 21 July 2025
Svalbard winter warming is reaching melting point
…
The Arctic is at the forefront of global climate change and is encountering unprecedented winter warming. In February 2025, exceptionally high air temperatures and rainfall over Svalbard triggered widespread snowmelt and pooling of meltwater. Increasingly frequent winter thaw events are reshaping Arctic landscapes, signaling a dramatic shift towards a new Arctic.
Accelerated winter warming and wetting
Svalbard is at the front line of the climate crisis, warming at six to seven times the global average rate. Human-caused global warming is particularly amplified in the Arctic, causing the climate in the Arctic to warm more quickly than the rest of the Earth. The winter period is experiencing the highest rates of warming with winter temperatures over Svalbard rising at nearly twice the annual average. Meanwhile, centennial trends for annual precipitation in west Svalbard show increases of 3–4 % per decade, of which a greater proportion is falling as rain. As such, over the past 40 years, rain-on-snow events have significantly increased, and rain is projected to become the dominant form of precipitation in the Arctic by the end of this century.
This year, Arctic winter air temperatures were among the warmest ever recorded. In Ny-Ålesund, the world’s northernmost permanent settlement, situated in north-west Svalbard and approximately 1,200 km from the North Pole, the air temperature average for February 2025 was -3.3 °C — considerably higher than the 1961-2001 average for this time of year of -15 °C (Fig. 1a), and reached a maximum of 4.7 °C. Air temperatures higher than 0 °C were recorded in Ny-Ålesund on 14 of the 28 days of February 2025 (Fig. 1b). Such sustained warmth, coupled with prolonged rainfall, triggered widespread melting of snow and ice. When winter warming crosses the 0 °C threshold, it marks more than just a warm anomaly — it signals a fundamental shift in Arctic winter dynamics. Episodic thawing events during winter can have significant and lasting environmental consequences, including influencing ice layer formation, triggering microbial activation, altering nutrient discharge, and affecting permafrost thaw and ground ice development. The episodic warming event of February 2025 was not an isolated occurrence: winter warming events in Svalbard have been a recurring phenomenon in recent decades as a consequence of anthropogenic climate change. As climate change continues to take hold, the frequency and magnitude of winter warming episodes will increase, and so will their effects on Arctic systems and societies.
Our teams are working in Ny-Ålesund to study glacial and terrestrial microbial communities and their role in carbon and other elemental cycles during the dark, frozen, winter period, for which data remains scarce. Our winter-time field campaigns in Svalbard are conducted under the expectation of sub-zero temperatures and extensive snow cover — conditions that have historically been typical in Svalbard during winter, but in recent years are increasingly threatened by climate change. However, in February 2025, we encountered air temperatures persistently above 0 °C, as well as rainfall, exceptionally low snow cover, and pooling meltwater covering the tundra. Wintertime warming and rain turned Ny-Ålesund and the surrounding landscape into a melting ice rink, disrupting planned sampling efforts, forcing adaptations in methodologies, provoking new scientific questions, and raising concerns about the long-term feasibility of our winter research practices and logistics under increasingly variable conditions and rising temperatures.
The new Arctic
Ny-Ålesund has been a hub for scientific research in the high Arctic for the last five decades. Researchers worldwide come to the remote Arctic outpost to study and monitor terrestrial and marine ecosystems, glaciers, and atmospheric processes, collecting vital information about the functioning of Arctic systems and their responses to ongoing anthropogenic pressures. Winter warming is leading to profound impacts on the Arctic system, and the changes are becoming evident. During this year’s winter field campaign, we directly observed meltwater pooling above frozen ground, forming vast temporary lakes (Fig. 2a). Glacier-fed streams and rivers that usually remain frozen until springtime became active. Snow cover on the tundra was reduced to zero across large areas (Fig. 2b). The reduced snow cover led to greater exposure of the bare ground surface (Fig. 2d). Vegetation emerged through the melting snow and ice, displaying green hues typically associated with spring and summer. Blooms of biological activity were widespread across the thawing tundra (Fig. 2d). Surface soils, which are typically frozen solid during this time of the year, thawed such that they were soft enough to be directly sampled with a spoon, rather than digging snow pits to the soil surface and using drills and pickaxes to extract frozen soil samples (which has been necessary during our normal wintertime sampling operations). The uppermost soils of the permafrost active layer (the active layer is the portion of the soil above permafrost that thaws during summer) were free of snow and thawing in multiple areas, further altering the stability of the terrain. At low elevations, warm temperatures and rainfall on the nearby glaciers diminished snow accumulation (Fig. 2c), and multiple ice layers in the remaining snowpack indicated to us that February’s melting event was not a one-off occurrence this winter.
…
Bradley, J.A., Molares Moncayo, L., Gallo, G. et al. Svalbard winter warming is reaching melting point. Nat Commun 16, 6409 (2025). https://doi.org/10.1038/s41467-025-60926-8
Svalbard winter warming is reaching melting point
…
The Arctic is at the forefront of global climate change and is encountering unprecedented winter warming. In February 2025, exceptionally high air temperatures and rainfall over Svalbard triggered widespread snowmelt and pooling of meltwater. Increasingly frequent winter thaw events are reshaping Arctic landscapes, signaling a dramatic shift towards a new Arctic.
Accelerated winter warming and wetting
Svalbard is at the front line of the climate crisis, warming at six to seven times the global average rate. Human-caused global warming is particularly amplified in the Arctic, causing the climate in the Arctic to warm more quickly than the rest of the Earth. The winter period is experiencing the highest rates of warming with winter temperatures over Svalbard rising at nearly twice the annual average. Meanwhile, centennial trends for annual precipitation in west Svalbard show increases of 3–4 % per decade, of which a greater proportion is falling as rain. As such, over the past 40 years, rain-on-snow events have significantly increased, and rain is projected to become the dominant form of precipitation in the Arctic by the end of this century.
This year, Arctic winter air temperatures were among the warmest ever recorded. In Ny-Ålesund, the world’s northernmost permanent settlement, situated in north-west Svalbard and approximately 1,200 km from the North Pole, the air temperature average for February 2025 was -3.3 °C — considerably higher than the 1961-2001 average for this time of year of -15 °C (Fig. 1a), and reached a maximum of 4.7 °C. Air temperatures higher than 0 °C were recorded in Ny-Ålesund on 14 of the 28 days of February 2025 (Fig. 1b). Such sustained warmth, coupled with prolonged rainfall, triggered widespread melting of snow and ice. When winter warming crosses the 0 °C threshold, it marks more than just a warm anomaly — it signals a fundamental shift in Arctic winter dynamics. Episodic thawing events during winter can have significant and lasting environmental consequences, including influencing ice layer formation, triggering microbial activation, altering nutrient discharge, and affecting permafrost thaw and ground ice development. The episodic warming event of February 2025 was not an isolated occurrence: winter warming events in Svalbard have been a recurring phenomenon in recent decades as a consequence of anthropogenic climate change. As climate change continues to take hold, the frequency and magnitude of winter warming episodes will increase, and so will their effects on Arctic systems and societies.
Our teams are working in Ny-Ålesund to study glacial and terrestrial microbial communities and their role in carbon and other elemental cycles during the dark, frozen, winter period, for which data remains scarce. Our winter-time field campaigns in Svalbard are conducted under the expectation of sub-zero temperatures and extensive snow cover — conditions that have historically been typical in Svalbard during winter, but in recent years are increasingly threatened by climate change. However, in February 2025, we encountered air temperatures persistently above 0 °C, as well as rainfall, exceptionally low snow cover, and pooling meltwater covering the tundra. Wintertime warming and rain turned Ny-Ålesund and the surrounding landscape into a melting ice rink, disrupting planned sampling efforts, forcing adaptations in methodologies, provoking new scientific questions, and raising concerns about the long-term feasibility of our winter research practices and logistics under increasingly variable conditions and rising temperatures.
The new Arctic
Ny-Ålesund has been a hub for scientific research in the high Arctic for the last five decades. Researchers worldwide come to the remote Arctic outpost to study and monitor terrestrial and marine ecosystems, glaciers, and atmospheric processes, collecting vital information about the functioning of Arctic systems and their responses to ongoing anthropogenic pressures. Winter warming is leading to profound impacts on the Arctic system, and the changes are becoming evident. During this year’s winter field campaign, we directly observed meltwater pooling above frozen ground, forming vast temporary lakes (Fig. 2a). Glacier-fed streams and rivers that usually remain frozen until springtime became active. Snow cover on the tundra was reduced to zero across large areas (Fig. 2b). The reduced snow cover led to greater exposure of the bare ground surface (Fig. 2d). Vegetation emerged through the melting snow and ice, displaying green hues typically associated with spring and summer. Blooms of biological activity were widespread across the thawing tundra (Fig. 2d). Surface soils, which are typically frozen solid during this time of the year, thawed such that they were soft enough to be directly sampled with a spoon, rather than digging snow pits to the soil surface and using drills and pickaxes to extract frozen soil samples (which has been necessary during our normal wintertime sampling operations). The uppermost soils of the permafrost active layer (the active layer is the portion of the soil above permafrost that thaws during summer) were free of snow and thawing in multiple areas, further altering the stability of the terrain. At low elevations, warm temperatures and rainfall on the nearby glaciers diminished snow accumulation (Fig. 2c), and multiple ice layers in the remaining snowpack indicated to us that February’s melting event was not a one-off occurrence this winter.
…