A Record of Decline
The Rhône Glacier, source of the Rhône River in the Swiss Alps, provides a measurable record of climate change. At its last major peak during the Little Ice Age around 1860, its tongue reached far down into the valley, ending about 3 kilometers farther and 600 meters lower in elevation than it does today. Since systematic surveys began in 1874, the glacier has been in a near-constant state of retreat. By 2016, its total length was measured at 9.7 kilometers.
The rate of retreat has accelerated dramatically. Between 1980 and 2016, the glacier pulled back approximately 1.3 kilometers, an average rate of about 36 meters per year. On a hot day, it can lose 10 to 12 centimeters of ice. This rapid melting led to the formation of a new proglacial lake at its snout, which first appeared in 2005 and is now the official source of the Rhône. By 2024, this lake had grown to a considerable size, measuring around 550 meters long and 400 meters wide. The glacier's overall volume has shrunk by an estimated 60% since 1850. This retreat is tracked by the Swiss Glacier Monitoring Network (GLAMOS), which uses methods like measuring changes in glacier length, mass balance, and volume to document the ice loss.
An Icy Patient
Human intervention at the glacier shows both its economic role and its vulnerability. Since around 1870, a family-run business has bored a 100-meter-long ice grotto into the glacier's side each year, allowing tourists to walk inside the ice. Because the glacier is constantly moving—at a rate of 30 to 40 meters per year—and melting, this tunnel must be re-drilled annually.
To protect this tourist attraction from accelerating summer melt, operators employ a desperate measure: covering a section of the glacier with enormous white geotextile blankets. These UV-resistant fleeces cover an area of about 50,000 square meters near the ice cave. The blankets work by reflecting sunlight, and studies have shown they can reduce local ice melt by 50% to 70%. While effective on a small scale, this solution is expensive and not feasible for saving the entire glacier. Critics also point out that the synthetic polypropylene sheets can break apart, polluting the new glacial lake and the headwaters of the Rhône River. The blankets are a symbol of an attempt to preserve a specific feature and and not a solution to broader environmental changes causing the glacier's disappearance.