The tropical glaciers of the Andes Mountains are rapidly retreating, the most severe in 11,700 years.

Tropical glaciers in the Andes Mountains have shrunk to their smallest area in 11,700 years. Bedrock samples show that these glaciers have retreated to an unprecedented extent. As sensitive indicators of climate change, tropical glaciers are experiencing the impacts of modern global warming. Rising temperatures at high altitudes may be the cause of this retreat. The Andes Mountains, a hotspot for tropical glaciers, are among the first to be affected.

Cosmogenic carbon-14 (14C) and beryllium-10 (10Be) in bedrock samples are used to estimate the timing of glacier retreat. The results indicate that most samples have only recently been exposed, indicating a significant reduction in glacier area.

These small, rapidly responding glaciers may be a harbinger of future shrinkage of global glaciers.