🌅 Alaska’s Glacial Melt Season Is Getting Longer

SOURCE

Wells et al. (2026)

WHAT TO KNOW

• Researchers at the University of Alaska Fairbanks used radar observations to track seasonal melt and shifting snowlines on more than 3,000 glaciers statewide from 2016 to 2024, finding that for every 1 degree Celsius (1.8 degrees Fahrenheit) increase in average summer temperature, the glacial melting season extends by about three weeks. The researchers say understanding melt extent and snowline movements is important because they serve as proxies for glacier mass balance, or the difference between the amount of snow and ice a glacier gains and loses over time, which helps scientists predict how much melt or snowline retreat can be expected in the future under various warming scenarios.

WHY IT MATTERS

• As you’d probably guess, a longer melting season translates into greater total ice loss for glaciers, impacting landscapes and freshwater systems, and ultimately intensifying the effects of global warming. The authors’ analysis of a heat wave in 2019 underscores just how quickly the changes can happen: the short-lived heat wave lasted from June 23 to July 10, pushing temperatures 20-30°F above average in many places. The extreme temperatures caused glacier snowlines to rise nearly 350 feet higher in elevation, retreating to a level typically reached about two months later in a normal year. As a result, bare ice and snow remained exposed for longer, leading to greater overall ice loss.

CONNECT THE DOTS

• The present study aligns with other work suggesting Alaska’s glaciers are struggling. A 2024 study by researchers in the U.K. found Alaska’s Juneau Ice Field, one of North America’s largest areas of interconnected glaciers, is melting twice as fast as it was before 2010, describing the finding as an “incredibly worrying” sign that land ice may disappear sooner than previously believed. Earlier this year, researchers at Colorado State University found increased melting is also causing Alaska’s glacial lakes to expand about 120% faster (i.e., more than twice as fast) today than they were from 1986 to 1999.