Glacial ice offers a detailed record of the atmosphere, preserved in discrete layers, providing researchers with a valuable tool for studying planetary history. A sample taken from a glacier in the European Alps dates back at least 12,000 years, making it the oldest ice yet recovered from the region.

Studies of glacial ice in Europe have revealed a surge in lead pollution at the height of the Roman Empire and a drop in pollen from when farming collapsed during the Black Death. Oxygen and hydrogen isotopes trapped in ice provide a record of past temperature, allowing scientists to document past climate change.

An ice core taken from Dôme du Goûter in France extends the glacial record back before the dawn of human civilization. “You have humans going from hunter-gatherers with a very low population through the development of agriculture, domestication of animals, mining,” said coauthor Joe McConnell, of the Desert Research Institute in Nevada. “And it’s right in the center of Europe — where much of Western civilization evolved.”

Taken in 1999, the 130-foot core sat in a freezer in France for more than 20 years before scientists brought it to the Desert Research Institute, where they were able to use specialized equipment to melt down the ice and study its chemistry layer by layer. The ice showed summer temperatures in the Alps were around 3.5 degrees C (6.3 degrees F) cooler before the end of the last ice age.

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