Switzerland - Five thousand years ago, a prehistoric person trod high up in what is now the Swiss Alps wearing goatskin pants, leather shoes and armed with a bow and arrows.

The unremarkable journey through the Schnidejoch pass, a trail 2756m above sea level, has been a boon to scientists but it would never have emerged if climate change were not melting the nearby glacier.

So far 300 objects dating back as far as the Neolithic or New Stone Age - about 4000 BC in Europe - to the later Bronze and Iron Ages and the medieval era have been found in the site's former icefields.

"We know now that the discoveries on Schnidejoch are the oldest of this kind yet made in the Alps," said Albert Hafner, an expert with the archaeology service in the Bern canton.

They have allowed researchers not only to piece together snapshots of life way back when but also to shed light on climate fluctuations in the past 6500 years - and, we hope, shed light on what is happening now.

"For us, the site is the most important find because we have this correlation between climate change and archaeological objects," Hafner said.

Martin Grosjean, executive director of a national network called Swiss Climate Research, added: "We know that people were only able to walk on this site when it was relatively warm. When it was too cold the glacier advanced and it was not a passable route."

Scientists have long known there were periods of warmer weather in the region but the artifacts allowed them to identify the years when the site would have been passable on foot.

According to Grosjean, such data could help to sharpen forecasts for the future by taking into account patterns of natural temperature fluctuation.

The treasure preserved in the icefields was discovered in 2003 after two hikers noticed a strange piece of wood lying on some stones.

It turned out to be a quiver - a case for arrows - made of birch bark and dating as far 3000 BC Hafner said it could be the most significant discovery at the site.

"It's the only quiver yet found that is made of birch bark. It is unique in Europe," he said.