The volume of Switzerland’s 1,400 glaciers has decreased by half in less than a century, and the retreat of ice is accelerating, according to a study.

For the first reconstruction of ice loss in the country over the 20th century, experts analyzed thousands of images taken from mountaintops between the two world wars and field measurements.

According to researchers from ETH Zurich and the Swiss Federal Institute of Forest, Snow, and Landscape Research, ice quantities halved between 1931 and 2016.

They have lost an extra 13% since 2016.

“Glacier retreat is quickening,” said co-author Daniel Farinotti, whose findings were published in the scientific journal The Cryosphere.

Important because it helps us to infer the glaciers’ responses to a warming climate.

Switzerland’s glaciers comprise almost half of the Alpine total.

In the first reconstruction of ice loss in Switzerland during the 20th century, the researchers used long-term observations of glaciers, measurements in the field, and aerial and submit images.

There were 22,000 photos taken from the peaks between the two world wars.

As only a few of Switzerland’s glaciers have been regularly studied over the years, the researchers were able to fill in the gaps by utilizing multiple sources.

Their research involved using decades-old techniques to compare the shape and position of images of terrain and measuring the angles of land areas using cameras and instruments.

The researchers compared the surface topography of glaciers at various times, which allowed them to calculate the evolution of ice quantities.

Researchers discovered that not all glaciers are losing ice at the same rate.

It was discovered that altitude, the amount of debris on glaciers, and the flatness of the glacier’s “snout” – its lowest, most susceptible portion – all affect the rates of retreat.

Two eras, the 1920s, and the 1980s exhibited intermittent rise in glacier mass, although this was eclipsed by the overall trend of loss.