在南极储存冰

Where do you keep ice? In the freezer, of course. That's what scientists might have thought when they were looking for a safe place to store ice from mountain glaciers from around the world. They've decided to store ice in Antarctica because global warming is causing some of the glaciers in places like the Alps to melt.

Jerome Chappellaz of the French National Centre for Scientific Research is involved in creating an ice vault there. He says: "We are probably the only scientific community whose archive is in danger of disappearing from the face of the planet. If you work on corals, on marine sediments, on tree rings, the raw material is still here and will be for many centuries".

And why do scientists need to study ice from the Alps, for example? Ice formed on the summit of a mountain is made of layers of snow accumulated over thousands of years. Trapped air bubbles contain samples of the atmosphere that existed when that ice was formed. Ice is a record of climate, according to polaroceanographer Mark Brandon from the Open University in Britain. He says: "We know carbon dioxide in the atmosphere is higher now than in the last three million years".

Researchers use this kind of data to build computer models and try to predict what might happen in the future.

The ice vault will be housed in a snow cave at the Concordia Research Station, which is operated by scientists from France and Italy. The ice samples will be sealed in bags and placed 10m below the surface, at a constant temperature of -50C. This will put the scientists' minds at rest. Commercial freezers break down, power failures happen and losing the ice samples would be a disaster. Nobody wants to see a mine of scientific knowledge lost for ever in a giant puddle.