In the past 150 years, the Rhône Glacier—a Swiss tourist attraction that feeds Lake Geneva—has shrunk badly. In the past decade, it has shed an average of 33 feet of ice thickness annually. To slow the loss, each spring nearby residents cover a section of the glacier with heavy-duty fleece, which reduces melting by up to 70 percent. The process is time-consuming and expensive—and very likely futile. Glaciologists say that the method will never be sufficient to save a whole glacier.

This article appeared in the January/February 2019 edition with the headline "Under Wraps."