An unstable glacier is threatening a picturesque Italian town after higher summer temperatures caused it to accelerate melting.
The mayor of Courmayeur, Stefano Miserocchi, has been forced to restrict access to a section of a popular hiking trail outside the town after experts monitoring the Planpincieux glacier reported it moving up to 50cm in one day.
They warned that a 250,000 cubic metre mass of the 1,327 square kilometre glacier is at risk of collapsing.
Should it collapse, it is not known if the glacier would fall in pieces or career down the mountainside in one chunk.
The glacier, which is located in the Alps on the Grande Jorasses peak of the Mont Blanc massif, straddles the borders of Italy, France and Switzerland and contains the highest peak in Western Europe.
Officials said unusually high temperatures during August and September had accelerated the ice melt of the ancient ice formation.
Daily temperatures were around 2C warmer than average throughout the last two months.
News of the potential collapse comes as a special report by the Intergovernmental Panel on Climate Change said glaciers around the world, outside of Greenland and Antarctica but including Europe, are losing 220 billion metric tons of ice a year.
The report said glacier melt is happening faster than before and is accelerating, adding if nothing is done to reduce greenhouse gas emissions, glaciers are set to shrink 36% between now and the end of the century.
Smaller glaciers, like those in the Alps, could lose up to 80% of their ice by the year 2100 in a worst-case scenario.