Glaciers on Alaskan ice sheet melting at ‘incredibly alarming’ rate, study finds

Glaciers are on the verge of irreversible retreat, researchers say.

Glaciers on a vast ice field in Alaska are melting twice as fast as measured a decade ago, with researchers saying the rate of ice loss is “extremely worrying.”

The research, led by scientists from Newcastle University in the United Kingdom and published Tuesday in Nature Communications, revealed how the volume of ice on the Juneau Icefield has declined dramatically since 2010 compared to decades before.

The Juneau Icefield is located 600 meters north of Juneau and extends to the border with British Columbia. It is the fifth largest icefield in North America.

Researchers looked at historical data to identify three periods when ice volume changed significantly.

According to the study, the Juneau Icefield glacier volume loss remained consistent from 1770-1979, at a rate of 0.65-1.01 cubic kilometers per year. In the second period, from 1979-2010, the ice volume loss increased to 3.08-3.72 cubic kilometers per year.

According to the study, the Juneau Ice Field’s glacier volume loss accelerated to 5.91 cubic kilometers between 2010 and 2020.

“It is extremely worrying that our study has shown a rapid acceleration in the rate of glacier loss in the Juneau Icefield since the start of the 21st century,” Dr Bethan Davies, lead author of the study and a lecturer at the University of Newcastle, said in Nature on Tuesday.

Davies explains why the region is less susceptible to accelerated ice formation due to climate change.

“The Alaskan ice sheets, which are mostly flat plateau ice sheets, are particularly vulnerable to accelerated melting as the climate warms. The ice loss is occurring across the entire surface, meaning a much larger area is affected,” Davies said.

The study found that 108 glaciers have completely disappeared from the Juneau Ice Field since 1770. Maps from 2019 also showed that all glaciers in the region have thinned.

“As glaciers on the Juneau Plateau thin and the ice retreats to lower elevations and warmer air, the feedback processes that this sets in motion are likely to inhibit future glacier growth,” Davies said. He said this could cause glaciers to “reach a tipping point and retreat irreversibly.”

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