The world’s glaciers are melting up to 100 times faster than any time during the last 350 years.

The findings, based on a study of Patagonia, South America, have worrying implications for millions of people who rely on the slow moving bodies of ice for fresh water.

The quantity of ice lost from the 270 Patagonian glaciers is equivalent to filling Windermere in the Lake district more than 1,700 times, the journal Nature Geoscience reports.

The researchers, led by Neil Glasser of Aberystwyth University, Britain, analysed the rocky debris left by glaciers on the sides of mountains to work out how big they once were — and how much ice has vanished, according to the Daily Mail.

Since the Little Ice Age ended in Patagonia in the middle of the 17th century, the 270 glaciers that now cover an area of at least 0.4 square miles have lost 145 cubic miles of ice.

Because water is denser than ice, that is equivalent to about 130 cubic miles of water.

“The glaciers have lost a lot less ice up until 30 years ago than had been thought,” said Glasser.

“The real killer is that in the last 30 years the rate of loss has gone up 100 times above the long term average. It’s scary.”

The professor, who carried out the study alongside researchers from the University of Exeter and Stockholm University, said the South American glaciers were at a similar latitude in the southern hemisphere as the Alps are in the northern hemisphere.

Glaciers in the Alps are also retreating and could be losing ice more quickly than many scientists realise. The same could be true elsewhere. Millions of people rely on the Himalayan glaciers for water.

“That’s the killer for the Himalayas,” said Glasser. “The melt in the short term is great for them as they get a lot of freshwater in the dry season but in the long term it will be a big problem.”