Journal of Geophysical Research: Earth Surface, 19 April 2022
Winter temperatures have increased by nearly 1°C in the Olympic mountain range over the past century, resulting in the disappearance of more than half its original glacial area. Glaciers in the Olympic mountains are particularly vulnerable to climate change due to both their low elevation, and near proximity to the Pacific Ocean. Local air temperatures in the northwestern United States — and therefore the glaciers — are strongly affected by warming surface temperatures of the nearby ocean. During the summer, high air temperatures accelerate glacier ice loss; and during the winter, warming causes more precipitation to fall as rain rather than snow, which reduces snow accumulation and slows glacier growth. The combination of rising air and ocean temperatures therefore has a compounding negative impact on the survival of these glaciers. Since 1980, the Olympic Peninsula has already lost 35 glaciers and 16 perennial snowfields. The remaining glaciers provide the only source of water for downstream alpine areas during the summer months, and their complete loss will trigger a chain of negative impacts extending through local ecosystems and human communities. This study provides a clear message that anthropogenic emissions have long-term and disastrous consequences on vulnerable snow and ice-covered regions.