Never before has the view of Austria’s glaciers been so sobering at the beginning of July: the white snow cover is missing in many places, bare ice lies exposed – and is melting unchecked in the midsummer sun.

“Normally, we measure the greatest snow depth of the year at the beginning of May,” says Andrea Fischer, glaciologist and deputy director of the Institute for Interdisciplinary Mountain Research at the Austrian Academy of Sciences (ÖAW) in Innsbruck. But this year, winter brought too little snow, spring too much warmth – and summer is now taking a heavy toll on the unprotected ice surface.

In the interview, the glacier expert talks about the “Glacier Diary” project, which documents the changes, the increasing instability in high mountain areas, and the role of science in times of climate crisis.

Snow-free Surfaces

How unusual is the current snow situation on Austria’s glaciers compared to previous years?

Andrea Fischer: As of May 1, there was unusually little snow – normally, that’s when we measure the annual maximum snow depth on glaciers. This year, many lower tongues were already snow-free, and even in high, north-facing areas melting had begun. The little snow that did fall came under dry, cold conditions and was carried away by wind – especially in the west. There was still some snowfall in June, but persistently high temperatures melted it away quickly. By early July, about half of the glacier surfaces in the west were snow-free – a situation that used to occur only at the end of the melting season, but now already at the start.

If high temperatures persist and no summer snowfall occurs – as in recent years – soon the entire surface will be snow-free. Without protective snow cover, the thin ice layers in the high regions will once again be severely eroded. In recent years, melt rates of up to two meters per year have been recorded there – with only 10 to 20 meters of ice thickness, this quickly leads to large area losses. I therefore expect another year of extreme ice loss.

Every day of exposed ice costs about ten centimeters of thickness.

So, if bare ice is visible as early as May, that means major losses?

Fischer: Exactly. Every day with exposed ice costs about ten centimeters of thickness. The longer this phase lasts, the greater the melt. What matters is not the valley temperature, but whether the ice above is uncovered – since around 70 percent of the melt energy comes from solar radiation, not air temperature. Recently, the freezing level has been very high, with temperatures above zero even at high altitudes. This means melting continues at night – the glaciers are melting practically around the clock.

What caused the snow cover to be so low this past winter?

Fischer: On the one hand, it was due to specific weather conditions, on the other hand to climate changes influencing their frequency. There were very few weather systems bringing heavy precipitation. The frontal zone lay unusually far north, leading to fewer snowfalls – and when precipitation did come, it was often too warm, so it rained instead of snowing. In some areas, it even rained up into glacier regions until mid-November. In the past, the frontal zone was further south, with more frequent snowfalls and lower temperatures. Added to this are very high ocean temperatures. This shows how strongly our weather is linked to global circulation patterns, the oceans’ energy balance, and sea ice.

Small Glaciers Especially at Risk

How are snow depths and ice losses actually measured?

Fischer: Around May 1, we measure how much snow has accumulated over the winter – from October to early May. In summer, we drill stakes into the ice and measure how much of them is exposed, in order to track melting at different points. In Austria, this is done in detail at more than ten glaciers. From this, we can calculate the annual mass balance.

In recent years, however, this has become more difficult due to increasing glacier instability and frequent mass movements. That’s why geodetic methods are used more and more, such as drone-based aerial surveys, to capture the overall balance.

In Austria there are about 900 glaciers – and by now, almost all are affected.

Which regions or glaciers are particularly impacted right now?

Fischer: Austria has about 900 glaciers – almost all of them are affected by now. The situation is especially critical for small, high-altitude glaciers that were long considered stable. But because they are usually very thin, melting is now progressing rapidly there as well. Some almost disappeared last year, and it’s questionable whether they will survive this summer. The large glaciers have been losing mass for decades, with their tongues now extremely thinned.

Unstable Glaciers

What does this record melt mean in the long run for water supply and ecosystems?

Fischer: Austria basically has sufficient precipitation. Climate change, however, shifts its distribution. Heavy rain is becoming more frequent, with consequences for water supply and natural hazards. Glacier meltwater plays only a small role here, as it is barely used and contributes little to the overall balance. In dry high mountain regions, it’s different – there it’s vital. Even here, however, instability in glacier environments is increasing and can in individual cases affect high-altitude settlements.

You mean rockfalls or mudslides?

Fischer: Yes, chains of events involving ice or dammed water can have particularly large impacts. Especially dangerous are debris flows from water accumulating in ice remnants, or mass movements hitting glacier remains, triggering avalanche-like events.

They prove: climate protection works – not immediately, but in the medium and long term.

How can a project like the “Glacier Diary” help raise public awareness of the climate crisis?

Fischer: Our job as scientists is to generate knowledge and make it accessible to the public. Especially in times of such rapid changes, it is important that everyone can understand what is happening and why. We all shape our future – through individual and societal decisions. That requires a solid, objective foundation: we need to know what we are choosing for or against. Modeling clearly shows how glaciers evolve under different greenhouse gas scenarios. They prove: climate protection works – not immediately, but in the medium and long term. Even if not everything is possible: every measure helps. Doing nothing would be the worst option.

Fourth Extreme Summer in a Row

What’s next for the Glacier Diary?

Fischer: This summer, we plan to publish updates about once a month to make the course of the melting season visible. It would already be the fourth extreme summer in a row. Even for us glaciologists, it’s exciting every year, because we are witnessing changes we couldn’t have imagined decades ago. That’s why it’s important to document this carefully: deglaciation is not only scientifically relevant, but also socially.