Italian authorities have closed roads and evacuated mountain huts after experts warned that part of a glacier on Mont Blanc could collapse. About 250,000 cubic metres of ice are in danger of breaking away from the Planpincieux glacier on the Grandes Jorasses peak. The mayor of the town of Courmayeur said global warming was changing the mountain. The Mont Blanc massif, with 11 peaks above 4,000m, is Western Europe's highest mountain range. Experts say it is impossible to predict when the glacier could collapse, as it goes through a period of major change due to climate factors. Earlier this month, dozens of people took part in a ‘funeral march’ to mark the disappearance of the Pizol glacier in north-east Switzerland. It has shrunk to a tiny fraction of its original size, losing 80% of its volume since 2006. See also ‘USA: UN general assembly’ in this week’s world section.