Samples of ice from Mont Blanc are to be sent to Antarctica where they will be preserved for future research because glaciers in the French Alps are melting at an accelerating rate.
Generations of scientists will be able to study climate change and the impact of pollution by using air bubbles trapped in the ice.
The samples, which will be kept at the Concordia Research Station, a French-Italian Antarctic base, will constitute "an invaluable scientific legacy", said Jean Jouzel, a climatologist.
Researchers will drop by helicopter some 4300m up on the Col du Dome glacier next month and will spend two weeks drilling to collect three samples up to 140m-long.
One will stay in a freezer in France and the others will go to the South Pole as "property of the international community".