Swiss researchers sound the alarm Glacier shrinkage is a "question of survival" for humanity

The melting ice is having devastating effects worldwide. Between 2012 and 2023, the shrinkage was 36 percent greater than in the previous ten years. The United Nations is highlighting the plight in 2025.

Worldwide, many of the approximately 275,000 glaciers are shrinking at an alarming rate, both in the mountains and in the polar regions. Between 2012 and 2023, the shrinkage was 36 percent greater than in the previous ten years, according to a study by the Swiss University of Fribourg. The main cause is man-made emissions of greenhouse gases that are warming the climate. To shake mankind awake, the United Nations has declared March 21 as World Glacier Day.

Some of the most serious consequences of glacier retreat:

Glacier meltwater is a crucial component in supplying the world's population with drinking water. Preserving them as sources of drinking water is a matter of survival for mankind, warns glaciologist John Pomeroy from the Canadian University of Saskatchewan.

Glaciers are reservoirs; meltwater feeds rivers in hot seasons, for example, which are also used to irrigate agriculture. Initially, the amount of water is growing due to the melting glaciers, but in Europe the peak could already have been passed, says glacier expert Daniel Farinotti, professor at the ETH University in Zurich and the Swiss Federal Institute for Forest, Snow and Landscape Research (WSL).

"The 273 billion tons of ice lost in a single year (due to glacier melt) correspond to the water consumption of the entire world population over 30 years, assuming three liters per person per day," the University of Zurich quotes glaciologist Michael Zemp.

At the entrance to Lake Geneva in Switzerland, water from the Rhone glacier accounts for around 15 percent over the year, says Farinotti. In Europe, a large proportion of drinking water comes from groundwater, which is mainly fed by precipitation. The exact role that snow and ice melt play in groundwater is still being researched.

Glaciers worldwide have lost around 273 billion tons of ice every year since 2000, according to a new study led by the University of Zurich. This has contributed 18 millimeters to sea level rise. This does not take into account the melting of the continental ice sheets of Greenland and Antarctica.

The annual sea level rise has more than doubled to around 3.6 millimetres since 2006 compared to the average value of the 20th century, reported the US climate agency Noaa 2023. Trend: rising. In addition to glacier and ice melt, the expansion of seawater due to warming is also contributing to this. Noaa assumes that sea levels will be around 30 centimetres higher at the end of the century than in 2000, even if greenhouse gas emissions remain at a relatively low level in the coming decades.

If sea levels rise, islands and coastal areas will be flooded, residential areas will become uninhabitable and arable land will be destroyed. Salty seawater can contaminate freshwater and therefore drinking water sources, and hurricanes cause greater damage when the water level is higher.

The mild climate in Europe and the distribution of precipitation worldwide is decisively influenced by the Gulf Stream, part of the Atlantic overturning current (Amoc). It brings warm ocean water to the north, where it cools and sinks, thus setting the Atlantic current in motion. The Intergovernmental Panel on Climate Change (IPCC) has warned that a collapse of the circulation could be triggered by unexpectedly large amounts of meltwater from polar glaciers.

A new study in the journal "Nature" suggests that the Amoc may not disappear completely, but that it will become significantly weaker. "Whether it ends up being a collapse or a very strong weakening makes hardly any difference to the effects of this change in the end," reports Jens Terhaar, who models the ecosystem of the Arctic Ocean at the University of Bern, among other things. "Both would have extreme consequences and we should do everything we can to avoid this."

Biodiversity changes dramatically in the area of mountain glaciers when the ice melts and temperatures rise. Heat-sensitive plants and animal species have to migrate higher. Cold-water inhabitants of rivers are threatened if their habitat is no longer cooled by glacier water.

"Some species don't like it when the water gets warm, and rivers could dry out to such an extent that fish and other aquatic life have no chance of survival," says Farinotti. The Swiss aquatic research institute Eawag writes that humans may also have to relocate sensitive river dwellers to higher altitudes. They would also have to be protected there. Areas released by glaciers should therefore not all be used as recreational areas or for the production of energy through hydropower.

Unknown microorganisms are constantly being discovered in glacier ice. What happens when the ice melts? Chinese researchers have documented DNA from more than 10,000 virus species in mountain and polar glaciers, which they claim do not pose a major threat to public health. In Swiss glaciers and permafrost, Beat Frey from WSL and colleagues have discovered ten new species of bacteria and one new species of fungus.

These organisms can provide information about past climate changes. The researchers are investigating whether they may also be useful in the fight against antibiotic-resistant germs. Frey and his colleagues also found that some bacteria were able to break down certain plastics at very low temperatures. "Our long-term vision is to find a solution to some global problems," Frey told swissinfo.ch.