Drilling down to the data of endangered glaciers

Global warming has accelerated the retreat of Alpine glaciers, including those in Switzerland, which have lost almost 40 per cent of their volume since 2000. Two catastrophic years, 2022 and 2023, obliterated ten per cent of Switzerland’s total glacier volume alone. Glaciers continued to shrink in summer 2024, even though the preceding winter had seen exceptionally high snowfall. The United Nations has named 2025 the International Year of Glaciers’ Preservation to highlight the urgency of the situation. The clock is ticking. Unless global warming is capped below 2°C, Switzerland’s glaciers may disappear altogether by the end of the century.

But even if global warming remains below 2°C, it still may only be possible to save a quarter of Switzerland’s current glacial ice by 2100. Glaciers contain information on how the Earth’s climate and our own environmental past have evolved over time. The chemical and biological compounds trapped in their deep layers of ice constitute a natural scientific archive dating back thousands of years. Preserving this information has become a race against time.

  
 
The world’s oldest ice core – on its way to Berne

At the beginning of 2025, a European research team in Antarctica successfully drilled a 2,800-metre-long ice core reaching all the way down to the bedrock. This continuous sample, extracted as part of the EU-funded Beyond EPICA project, provides an unprecedented record of the Earth’s climate spanning over 1.2 million years. Initial analyses suggest that at least 13,000 years of data are compressed into one metre of ice.

The University of Bern has a hand in the project. Its Climate and Environmental Physics division specialises in measuring greenhouse gas concentrations found in small air bubbles that are trapped in the ice. “We can begin our studies in autumn,” says climate physician Hubertus Fischer, who is looking forward to taking receipt of the Antarctic samples and gaining a new awareness of the Earth’s ice age cycles. “There was an ice age every 40,000 years around 1.5 million years ago. As we know, this cycle later slowed to 100,000 years.”

-50°C in the storage room

Researchers want to know why – and Fischer believes that greenhouse gases provide the smoking gun. “If we have a better understanding of what happened in the past, we will be more able to predict what may happen in the future.”

The valuable cargo from Antarctica is expected to arrive in Berne this summer. To house the ice, the university has built a bespoke new cold store with an ambient temperature of -50°C. Ice samples in Berne have been stored at a temperature of -25°C until now. “The ice must be kept in very cold conditions for certain analyses. This prevents the properties of the ice from changing,” Fischer explains. An emergency generator maintains the cold chain in the event of a power cut.

Scientists in Antarctica cut the ice core into one-metre-long sections, before the cargo was shipped northwards through the sweltering tropics of the Atlantic and across the Mediterranean to Italy – at a temperature of -50°C. The journey continued overland to the northern German city of Bremerhaven, where the samples were cut into even smaller pieces at the Alfred Wegener Institute, before being sent on their way to participating research centres around Europe, including Berne.

(TP)

www.beyondepica.eu