A flea market is an unusual place for a geologist to begin working on a research project on mountain glaciers. But for a Munich-based team of geological climatologists, this is the perfect starting point.
Three years ago the German team of scientists began searching antique stores, flee markets, state archives and university libraries for historic photos and postcards. They collected 2,500 examples from across Europe. And every illustration depicted the exact same thing: Alpine glaciers.
The scientists, working together with Greenpeace, are using the historic pictures as proof of climate warming in Europe. By comparing the old photos with pictures taken from today, the Munich Society for Environmental Research can show how rapidly the glaciers have melted over the course of years. The data they gain will be used by climatologists as proof of global warming.
Taking the global temperature
According to the World Glacier Monitoring organization, glaciers are a "global thermometer" and reflect the world’s rising temperature. "They are the most visible sign of climate change," says the Munich team’s Web site.
From the middle of the 19th Century to about 1975, the giant ice fields shrank about one-third in area and lost about half of their volume. In the last 25 years, they have melted even faster, losing an additional 20 to 30 percent of their water content.
The disappearance of the Alpine glaciers effects more than just the mountain eco-system. Europe’s biggest rivers, the Rhine, Rhone and Po, spring forth from the glaciers and depend on their year-round water supply.
If the glaciers dry up, entire water reservoirs will be endangered, warn the Munich researchers. Plus, the melting ice fields loosen up boulders and lead to mountainside erosion and eventually avalanches.
For the experts meeting in Johannesburg at the end of August for the U.N. Climate Summit, the shrinking mountain lakes are a key indicator of global warming and a cause for world-wide concern, says the Society for Environmental Research in Munich.
Relocating historical sites
But documenting the glacial melt is not an easy task. The scientists have to find the exact location depicted in the historical photos and the position from which the picture was taken.
To do so, the geologists spent months hiking through the Alps, speaking with mountain guides and local climbers. They studied elevation maps, examined satellite images, and measured paths and meadows.
Equipped with the most modern surveying technology such as UV- gauges on the one hand and historic hiking maps on the other, the team was finally able to locate the 60 largest Alpine glaciers shown in the postcards.
"We had to do a lot of climbing and clambering," the team’s project leader, Wolfgang Zängl, told the German newsweekly Der Spiegel.
Many of the key landscape markers shown in the photos, such as rock formations and boulders, are covered in grass and trees, explains team member Sylvia Hamberger. "The old hiking paths and glacier terraces have disappeared" making orientation difficult in the mountain landscape, she says.
In the end, though, the team was able to photograph each one of the glaciers and compare the size and shape of today’s frozen lakes to those in the historical photos. The results of their research and the glacial photo documentation have been published on the Internet under the Web site www.gletscherarchiv.de.
Looking at the pictures, the differences between then and now are obvious. The pictures tell the whole story -- the glaciers are rapidly disappearing.
"We are witnesses to the fastest glacial melting in a thousand years," the Society for Environmental Research writes on their Web site. "But today we are lucky that we can still see the glaciers."