Permanent Change to Alaska Sparks Alarm

Parts of Alaska may be undergoing lasting environmental changes as rising temperatures thaw the frozen ground beneath the Arctic landscape—with implications that go well beyond "

The Last Frontier." This is the warning of a first-of-its-kind study by researchers led by geoscientist professor Michael Rawlins of the University of Massachusetts Amherst, who examined what happens when Arctic permafrost melts — and how this thawing is reshaping Alaska’s waterways. The team focused on a Wisconsin-sized stretch of Alaska’s North Slope which is home to hundreds of rivers and streams that flow into the Beaufort Sea.

By analyzing 44 years of model data at a one-kilometer grid resolution, the team tracked changes in runoff, the movement of long-frozen carbon into rivers and the lengthening of the permafrost thawing season into late summer and fall.

“What makes this question so hard to answer is that direct observations are very sparse in northern Alaska,” said Rawlins in a statement.

“There are nowhere near enough river sample measurements to quantify inputs to estuaries along the entire Alaskan North Slope.” Arctic rivers play an outsized role in the planet’s ecosystem. They deliver roughly 11 percent of the world’s river water into an ocean that contains just one percent of the planet’s total ocean volume, making the region particularly sensitive to changes upstream.

While much of that water comes from melting snow, thawing permafrost also contributes significantly. Despite its name, permafrost is not frozen solid all year round; instead, its upper section, called the “active layer,” thaws each summer and refreezes in winter. As the climate warms, howver, the active layer is deepening, allowing more groundwater to flow into Arctic rivers.

The active layer also holds enormous stores of frozen organic carbon. When it thaws, carbon in the form of dissolved organic carbon (DOC) is released into rivers and carried toward the ocean. The Arctic Ocean already receives a disproportionate share of DOC from rivers worldwide, and more than 275 million tons of this carbon are released as carbon dioxide each year — intensifying global warming.

To overcome the lack of on-the-ground data, Rawlins has spent decades developing the Permafrost Water Balance Model, a tool that estimates snow accumulation and melt, groundwater flow, changes in the active layer and other variables. In 2021, the model was expanded to simulate dissolved organic carbon.

“We’ve typically run the model on 25-kilometer grid cells,” says Rawlins.

“This new study is the first time anyone has captured such a wide area of the Arctic—about the size of Wisconsin—down to the kilometer scale, and over such a long period of time: our model simulates daily river flows and coastal exports over 44 years from 1980 to 2023.” Running that level of detail requires immense computing power. Each model run takes 10 continuous days on a supercomputer at the Massachusetts Green High Performance Computing Center.

Rawlins says the payoff is data that can be used by researchers and conservation groups studying coastal ecosystems in northern Alaska.

“Our freshwater and DOC inputs to coastal estuaries will be useful to a broad range of stakeholders interested in these unique ecosystems in coastal northern Alaska,” he says. The study found that while runoff and thawing are increasing across the region, the sharpest increases in carbon export are coming from northwest Alaska.

“It’s flatter over there, which means there’s much more carbon from decaying matter in the permafrost that has been accumulating for tens of thousands of years," said Rawlins.

He continued: "

This is ancient carbon. The further east you go, the more mountainous it becomes. The soil is rockier and sandier, and so far less DOC is mobilized as the permafrost thaws.”

One of the most striking findings is how long the thaw now lasts. The researchers found that permafrost thaw is extending into September and even October — weeks longer than in the recent past — fundamentally changing how water and carbon move through the landscape. These shifts are likely altering the salinity, chemistry and food web relationships in the Beaufort Sea.

Rawlins and his colleagues are now investigating how thawing polygonal patterns of ice wedges , which are widespread across the Arctic, may further affect the flow of water and carbon to coastal areas.

“How much DOC finds its way to the ocean via rivers and streams is a part of the carbon cycle we don’t know much about,” says Rawlins.

“We desperately need more of these land-to-ocean connection studies if we’re to fully grapple with the problem of global warming and the effects it will have on coastal ecosystems.” Do you have a tip on a science story that Newsweek should be covering? Do you have a question about climate change?

Let us know via science@newsweek.com. Rawlins, M. A., Connolly, C. T., & McClelland, J. W. (2026). Hydrological Cycle Intensification and Permafrost Thaw Drive Increased Freshwater and Organic Carbon Inputs to Northern Alaska Estuaries.

Global Biogeochemical Cycles, 40(4). https://doi.org/10.1029/2025GB008822