Disappearing glaciers of the Oregon Cascades, USA

Anders Carlson, Nicolas Bakken-French, Megan Thayne, Sam Pappas, Daniela Molnar, Dylan H. Rood 

The Oregon Cascades had 35 named glaciers on seven volcanos in the 1980s, with 34 of those glaciers remaining by 2000. Here we document the glaciers that fall into the Global Glacier Casualty List categories based on five years of field observations of these 34 glaciers. Five glaciers have disappeared, four have almost disappeared, and eight are critically endangered. Thus, half of the Oregon Cascade named glaciers have disappeared, almost disappeared, or reached critically endangered status in the 21st century. Between 1980 and 2024, the May-October ablation season of the Oregon Cascade region warmed at ~0.3°C per decade, with a 2020-24 mean temperature ~1.7°C warmer than the 1975-84 mean. In contrast, there was no significant trend in November-April accumulation season precipitation. Given the significant rise in melt-season temperature, we attribute ongoing glacier disappearance in the Oregon Cascades to the warming climate.