This Danish archive holds 25 kilometres of ancient ice

Nestled within the University of Copenhagen lies a remarkable treasure trove: 25 kilometers of ancient ice, some dating back hundreds of thousands of years. This frozen archive, held in 2,000 boxes, is more than just a chilly relic of the past. It's a key to unlocking the planet's climate history and predicting the future of its delicate balance.

As glaciers and ice sheets form, they trap tiny air bubbles, preserving snapshots of the atmosphere at that time. These bubbles, along with other clues like dust particles and plant DNA, create layered records like the rings of a tree. Each layer tells a story, whispering secrets about temperatures, volcanic eruptions, and even ancient winds.

Within the ice lie hidden clues: isotopes of oxygen and hydrogen. These natural elements act like tiny thermometers, revealing past temperatures with remarkable precision. By studying these isotopic ratios, scientists can rewind time and experience the Earth's climate in a bygone era.

This ancient ice isn't just a relic of the past; it's a vital tool for understanding the present and predicting the future. By comparing pre-industrial air samples to today's atmosphere, scientists can gauge the impact of human pollution on the climate.

This invaluable data helps refine climate models and forecast the potential effects of continued warming on sea levels, weather patterns, and ecosystems.