For centuries, Swiss farmers have sent their cattle, goats and sheep up the mountains to graze in warmer months before bringing them back down at the start of autumn. Devised in the Middle Ages to save precious grass in the valleys for winter stock, the tradition of “summering” has so transformed the countryside into a patchwork of forests and pastures that maintaining its appearance was written into the Swiss Constitution as an essential role of agriculture.
It has also knitted together essential threads of the country’s modern identity: alpine cheeses, hiking trails that crisscross summer pastures, cowbells echoing off the mountainsides.
In December, the United Nations heritage agency UNESCO added the Swiss tradition to its exalted “intangible cultural heritage” list.
But climate change threatens to scramble those traditions. Warming temperatures, glacier loss, less snow and an earlier snow melt are forcing farmers across Switzerland to adapt.
Not all are feeling the changes in the same way in a country where the Alps create many microclimates. Some are enjoying bigger yields on summer pastures, allowing them to extend their alpine seasons. Others are being forced by more frequent and intense droughts to descend with their herds earlier.
The more evident the effect on the Swiss, the more potential trouble it spells for all of Europe.
Switzerland has long been considered Europe’s water tower, the place where deep winter snows would accumulate and gently melt through the warmer months, augmenting the trickling runoff from thick glaciers that helped sustain many of Europe’s rivers and its ways of life for centuries.
Today, the Alps are warming about twice as fast as the global average, according to the Intergovernmental Panel on Climate Change. In the past two years alone, Swiss glaciers have lost 10 percent of their water volume — as much as melted in the three decades from 1960 to 1990.
Since he started studying the Rhône Glacier in 2007, Daniel Farinotti, one of Europe’s premier glacier scientists, has seen it retreat about half a kilometer, or about a third of a mile, and thin, forming a big glacial pond at its base.
He has also seen the glacier — which stretches around nine kilometers, or about five and half miles, up the Alps near Realp — grow black as protective winter snow melts to reveal previous years of pollution in a pernicious feedback loop.
“The darker the surface, the more sunlight it absorbs and the more melt that’s generated,” said Mr. Farinotti, who teaches at ETH Zurich and who leads a summer field course on the glacier.
To get to the glacier from the road, his students walk across mounds of white tarps, stretched around an ice cave carved for tourists. The tarps can reduce annual melting by as much as 60 percent, but they cover only a minuscule portion of glaciers, and in places like ski slopes, where there is a private financial motivation.
“You cannot cover an entire glacier with that,” said Mr. Farinotti, who also works for the Swiss Federal Institute for Forest, Snow and Landscape Research.
