article_snippet.sent: Research suggests that rockfall son Mont Blanc (pictured) are caused by warming temperatures .
article_snippet.sent: Climbers have long suspected that hotter summers trigger rockfalls on the slopes of Mont Blanc in the French Alps.
article_snippet.sent: Now a study of 533 rockfalls reported by climbers or spotted on satellite images of the mountain since 2003, has bolstered the opinion that climate change is making popular routes up Europe's highest mountain more treacherous.
article_snippet.sent: Ludovic Ranavel of the University of Savoie at Le Bourget-du-Lac in the French Alps, spotted a strong correlation between the number of rockfalls and air and rock temperatures on the slopes, New Scientist reported.
article_snippet.sent: New Scientist thinks that melting permafrost may be to blame, because it loosens rocks that were held in place with ice, causing them to fall.
article_snippet.sent: The expert revealed that 95 per cent of rockfalls around the mountain occur during between June and September - the hottest months of the year.
article_snippet.sent: As the French Alps get hotter, the zone containing perma ice is thought to be receding, creating more rockfalls than before.