Glaciers in the American West: 300 have disappeared

A new study published in the Proceedings of the National Academy of Sciences reveals that more than 300 glaciers have disappeared from the lower 48 United States due to rising temperatures. Since the mid-20th century, when approximately 1,450 glaciers existed in the American West, their combined surface area has decreased by 35%.

Glaciers in the western United States are melting faster than those in other parts of the world. This accelerated loss is attributed to the relatively small size of most glaciers in the lower 48 states, which makes them more vulnerable to warming. Washington state holds the largest concentration, covering about 114 square miles, while glaciers in the Beartooth-Absaroka Mountains of Montana are losing roughly 1.5 feet of ice thickness annually.

While these glaciers occupy a modest total area, they play a critical role in regulating rivers, supporting ecosystems, and maintaining freshwater supplies. The ongoing retreat is driven by increased summer melting and warmer winters that reduce snowfall.