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Warming soil temperatures in Alaska have implications for both climate change and infrastructure like roads and pipelines.
Photo Credit: Jim Black
Scientific Frontline: Extended "At a Glance" Summary: Soil Warming in Alaskan Permafrost
The Core Concept: Recent research demonstrates that soil temperatures across Alaska are rising rapidly and at considerable depths, with the fastest and most severe warming occurring within high-latitude continuous permafrost regions.
Key Distinction/Mechanism: Unlike lower-latitude regions where deep winter snow cover insulates the ground and buffers it from rising air temperatures, the permafrost regions lack this deep snowpack, allowing the underlying soil to absorb more thermal energy and exhibit significant, long-term warming trends even deep underground.
Origin/History: Published in the journal Frontiers in Climate in 2026, this comprehensive analysis by Washington State University synthesized 27 years of continuous air and soil temperature data collected from 43 weather stations across Alaska between 1997 and 2023.
Major Frameworks/Components:
- Polar Amplification: The climatic phenomenon where both air and soil temperatures in Arctic latitudes rise at roughly twice the rate of those in temperate southern regions.
- Greenhouse Gas Feedback: The mechanism by which thawing permafrost releases ancient, stored carbon dioxide and methane into the atmosphere, creating a feedback loop that drives further global warming.
- Snow Cover Buffering: The theoretical framework demonstrating that the depth of winter snow inversely correlates with the rate of winter soil warming.
- Deep Thermal Storage: The finding that long-term warming trends are more consistent and obvious at greater soil depths (e.g., 4 feet) than at shallower surface levels, where temperatures fluctuate seasonally.
Branch of Science: Soil Science, Climatology, and Environmental Science.
Future Application: Understanding the precise seasonality and depth of these warming trends will allow civil engineers to adapt critical Arctic infrastructure, such as roads and pipelines, against winter thaw cycles, while helping agricultural planners optimize extended summer growing seasons at lower latitudes.
Why It Matters: The destabilization of continuously frozen ground immediately threatens the structural integrity of Alaskan infrastructure and fundamentally transforms Arctic soil from a massive carbon and thermal sink into an active accelerator of global climate change.
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| Erin Oliver, a postdoctoral research associate for WSU’s Department of Crop and Soil Science, led a study of soil temperatures in Alaska from 1997 to 2023, finding that warming is occurring most quickly in the state’s permafrost regions. Photo Credit: Courtesy of Erin Oliver |
Soils are warming quickly and at considerable depth across Alaska, with temperatures rising fastest in the state’s permafrost region, a trend that could accelerate climate change and undermine the stability of roads, buildings, and other infrastructure built on the continuously frozen ground.
That’s a central finding of new research from Washington State University that provides a comprehensive look at soil temperatures from 1997 to 2023 in a state where the effects of climate change are pronounced. The warming permafrost is of particular concern because when that ground thaws, it releases carbon dioxide and methane, driving even faster warming.
Alaska’s air temperatures are rising at twice the pace of the Lower 48, a key sign of the “polar amplification” of climate change at the Arctic latitudes. The new research details how and where the ground is warming, compares that to air temperatures, and shows that snow cover plays a key role in regional differences.
“In the Lower 48 or farther south, you would expect that soil temperatures and air temperatures would change at the same rate,” said lead author Erin Oliver, a postdoctoral research associate for WSU’s Department of Crop and Soil Science who is based in Alaska. “Those warmer air temperatures warm the soil. But in Alaska, over half the year, our soils are covered in snow. So how would that affect things?”
In short, her study found that soil warming is almost keeping pace with air warming, particularly in the central and maritime parts of the state. In high-latitude permafrost regions, soil warming is lagging behind air warming, but even so, she saw “polar amplification” in soil temperatures, too.
Over the 27 years of the study, air and soil temperatures increased across the state, but the increases were most pronounced in the permafrost regions, where air temperatures rose at a rate of 1.15 degrees Celsius per decade and soil temperatures rose at 0.64 degrees Celsius per decade.
The research, published in the journal Frontiers in Climate, offers one of the most comprehensive studies of the relationship between air and soil temperatures in Alaska. The collection of such data is difficult in the state due to its vast size and challenging geography.
“It’s hard to get around in Alaska,” Oliver said. “Most of the state is very remote; it’s very expensive to put in these weather stations, and they really only started putting them in during the late 1990s. So, comparatively, we don’t have as much of a record as other places.”
For the study, the researchers synthesized air and soil temperature data from 43 weather stations across Alaska and tracked soil temperatures at several different depths over 27 years. To evaluate the effects of snow cover, they divided the state into three regions: one with continuous permafrost, one with some areas of permafrost, and one without permafrost. In the latter two categories, soil temperatures rose at roughly half the rate seen in the permafrost regions.
That suggests that snow cover, which is deeper at lower latitudes than at higher latitudes during the winter, slows the rate of warming, providing a buffer to changes in air temperature.
“A neat result was that soil warming rates weren’t slowing down deeper in the soil,” said Oliver’s coauthor, Claire Phillips, a research soil scientist at WSU. “People tend to think that soil temperatures are more stable as you go deeper. The seasonal fluctuations do drop out, but the long-term warming trend was actually more obvious at depth.”
In the permafrost region, they found 100% of weather stations had a warming trend at a 4-foot depth, while only 65% of them had warming at 2 inches, where temperatures swing more from year to year.
“When you go through the numbers and you find permafrost soils showing 2 to 3 degrees Celsius per decade warming at a 4-foot depth in the winter months, that’s upsetting,” said Phillips. “But I also look at it as one of the ways this amazing planet is buffering us. The soil is storing a lot of heat that would otherwise all be held in the atmosphere.”
The findings can be used to help inform planning and policymaking in Alaska as the climate changes and brings about a range of different effects.
“In the permafrost region, most of the warming was in winter, and that will obviously have big effects on infrastructure,” Oliver said. “But in lower latitudes, most of the warming was in the summertime and could lead to an increase in our growing season. So knowing the seasonality of it can help Alaskans to adapt.”
Published in journal: Frontiers in Climate
Title: Significant soil warming across Alaska permafrost and non-permafrost regions from 1997 to 2023
Authors: Erin E. Oliver, and Claire L. Phillips
Source/Credit: Washington State University | Shawn Vestal
Edited by: Scientific Frontline
Reference Number: agri100126_01
