First a little snow in winter, then several heat waves in summer - this year the glaciers in the Alps have already lost an extremely large amount of ice, and the final measurements are still ongoing. It could be one of the worst years for Alpine glaciers since systematic records began.
This new interactive map shows how dramatically the glaciers are retreating, not only in the Alps but worldwide.
Led by ETH Zurich and the Vrije University in Brussels, an international team of researchers has compiled scientific data and forecasts on the development of more than 200,000 glaciers.
Lander Van Tricht, the head of the project, points out that figures on glacier sand often seem very abstract. “This website allows users to zoom into their own valley or mountain region and see what different levels of global warming may mean for the glaciers around them.”
Because glaciers are more than just large masses of ice. They shape landscapes and ecosystems and are an attraction for tourists. Their meltwater feeds the rivers in summer, which contributes to the water supply and makes inland shipping possible in many places. In addition, there is often a strong cultural and emotional significance for the local population.
"Behind every disappearing glacier there is a place, a story and often a community that will feel its loss," says Van Tricht, warning: "Glacier extinction is not a distant problem at the end of the century. It is happening now."
According to the researchers, the map is the first global assessment of glacier loss and shows that the world is heading towards a period of unprecedented glacier loss. For each individual glacier it is listed when it is expected to disappear and how much this point depends on future warming.
Visible consequence of climate change
With global warming of 1.5 degrees Celsius, it is predicted that around 2,000 glaciers will disappear worldwide every year. At four degrees, this number should roughly double. In the four-degree scenario, more than 90 percent of today's glaciers would have disappeared by the year 2100. According to the researchers, only 20 glaciers would then remain in the Alps.
A glacier is considered to have disappeared if it has lost 99 percent of its original ice volume or if its ice area is less than 10,000 square meters.
The retreat of glaciers is one of the clearly visible consequences of climate change. From the Andes to the Alps to the Himalayas, the ice masses are shrinking. According to calculations by the World Glacier Monitoring Service, more than 9,000 gigatons of glacier ice have disappeared worldwide since the mid-1970s (one gigaton equals one billion tons).
A glacier only exists permanently if there is a balance between snowfall in winter and melting in summer. Rising temperatures extend the melting period and shorten the time in which new snow can accumulate.
In addition, as a result of climate change, more and more precipitation in many mountain regions is falling not as snow but as rain, which means that the glaciers are running out of supplies and are becoming smaller and smaller.
Now glaciers have always been changing. Their expansion reached its maximum about 20,000 years ago, at the height of the last ice age. Large parts of North America and northern Europe were covered by massive ice sheets. According to the Alfred Wegener Institute for Polar and Marine Research, sea levels were more than 100 meters lower than today.
Around 10,000 years ago, these large glaciations had largely disappeared and sea levels had risen accordingly. Today's warm period climate began. Since then, there have been warmer and cooler phases in which glaciers have retreated or expanded - worldwide and in the Alps.
Spectacular evidence of the dynamic history of the Alpine glaciers is the glacier mummy Ötzi, which was found in 1991 in the Ötztal Alps on the border between Austria and Italy. The man died at the end of the so-called Holocene climate optimum around 5,300 years ago.
Shortly after his death, his remains were covered by ice from the advancing glaciers and preserved for thousands of years. In the 16th and 17th centuries, the glaciers reached their greatest extent at the height of the so-called Little Ice Age.
The fact that the mummy is now reappearing in the melting ice shows how much the glaciers are currently retreating. While in the past the ice masses responded to climate changes over periods of centuries and millennia, the glaciers are currently retreating within decades.
Extremely hot summers like 2022 and 2026 will accelerate this process. Where there are no glaciers, there is also no water reservoir. Entire regions will have to adapt to using less water.
And for this, says Van Tricht, it is important to record the expected glacier losses. The interactive map is intended to provide orientation. Van Tricht: “We hope it will also help local communities prepare for a future with fewer glaciers.”
