In Antarctica, a frozen vault holds the secrets of the world’s vanishing glaciers - CNN

- Scientists are preserving ice cores from endangered glaciers in a vault carved deep beneath Antarctica's frozen surface.

- The Ice Memory Foundation is storing cylinders of ancient ice, protecting climate records stretching back millennia.

- These cores can reveal past atmospheric conditions and could unlock new discoveries.

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Beneath Antarctica’s endless white plateau, hidden deep within the snow, lies a priceless archive of the world’s climate memory.

The vault is not made of steel or concrete. There are no security systems or humming freezers. Instead, the sanctuary is carved directly into the Antarctic snow near Concordia Research Station, a remote Franco-Italian outpost more than 1,000 kilometers (620 miles) from the nearest coastline.

Inside the frozen cave, scientists are storing cylinders of ancient ice extracted from some of the world’s most endangered mountain glaciers. Within the ice are records of past climate history — from volcanic eruptions and wildfire smoke to industrial pollution and shifting atmospheric conditions stretching back centuries, sometimes millennia.

The project, led by the Ice Memory Foundation, aims to preserve pieces of these glaciers before rising temperatures erase them.

“It’s a unique location. It’s a unique idea. It’s really a first in many aspects,” Thomas Stocker, president of the foundation and professor of climate and environmental physics at the University of Bern, Switzerland, told CNN.

“We cannot save the entire glacier, but we can save the environmental and climate information that is stored in these glaciers.”

Predicting future climate change using ice cores

That information is preserved in microscopic air bubbles trapped inside the ice. “These bubbles are full of atmospheric air from the time this bubble was formed — maybe a hundred years, a thousand years, a million years back in time,” he said.

Scientists can analyze those bubbles to reconstruct historical concentrations of carbon dioxide, methane and other greenhouse gases. Stocker said ice core records have revealed that today’s carbon dioxide levels are 30% to 35% higher than at any point in the last 800,000 years. But records containing other important information are fading away.

“I’m living in Switzerland, so we have observed for many decades that the glaciers are retreating at an accelerating pace,” he said. “The local climate archives, such as in Alpine glaciers or in glaciers in the Himalayas or in the Andes, are disappearing at an alarmingly accelerating rate.”

Globally, thousands of glaciers have disappeared in recent decades and by the middle of the century, up to 4,000 glaciers could vanish each year if humans continue to drive climate change, according to a 2025 study. Roughly a decade ago, as the scale of glacier loss became increasingly clear, scientists developed the idea for the Ice Memory archives. Since then, teams have traveled around the world drilling and transporting fragile cores to Antarctica, where the continent’s natural cold can preserve them for centuries.

Collecting and transporting the samples to Antarctica while keeping them frozen and uncontaminated is a complex task that often requires expeditions into some of Earth’s harshest environments.

Scientists haul nearly 1,000 pounds of drilling equipment onto high-altitude terrain. In Tajikistan, one recent drilling campaign took place at 5,820 meters (19,094 feet) above sea level.

“You can imagine how difficult the working conditions for the drillers and the scientists who went there must have been,” Stocker said.

A cylindrical drill fitted with ring-shaped cutters bores into the glacier, extracting a vertical core of ice layer by layer. The deeper the core, the older the climate history it contains.

But before any drilling begins, scientists spend months surveying glaciers using ground-penetrating radar to identify the most stable locations, where the internal ice layers remain undisturbed.