What a 2,600-year-old pine needle can tell us about the melting Alps

Glaciers in the Alps are melting twice as fast as those in other parts of the world. (Flickr/Tormod Ulsberg)

The glaciers of the Alps are melting – and at twice the rate of other glaciers around the world. But what did those glaciers look like in the past? The retreat of glaciers can reveal important data about our climate’s past.

High up in the eastern Alps, near the Swiss-Italian border, glaciologists are drilling into snow and ice to extract ice cores, which can uncover the region’s climate history. Under the highest glacier in the eastern Alps, Alto dell’Ortles, researchers have discovered evidence of a changing climate.

That’s 262 feet below the surface of the glacier, to be exact. There, a conifer needle encased in solid ice was recently found. Carbon dating indicates that the needle is 2,600 years old. In other words, it tells us that for at least 2,600 years, this glacier, and likely others in the region, have remained frozen.

Frozen ice extends up from the bedrock to a level 98 feet below the surface of the glacier, where material is found that corresponds to the early 1980s. At that level the scientists started to find layers composed of grainy, compacted snow – indicating the glacier had partially melted and then refrozen.

Paolo Gabrielli, one of the research scientists working on the project, reported this evidence of “current atmospheric warming at high elevation in the Alps is outside the normal cold range held for millennia.”

When analyzed for dust and trace metals, these ice cores will offer up more clues about the region’s past climate. And because annual layers can be detected in the ice cores, they can yield a high-resolution climate record.

The team will also investigate the question of why glaciers in the Alps are disappearing faster than those found around the world.

“Ortles offers us the unique possibility to closely verify if and how regional environmental changes can interact with climatic changes of global significance,” Gabrielli said.

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