Switzerland's glaciers suffered their second worst melt rate this year after record 2022 losses, shrinking their overall volume by 10 percent in the last two years, monitoring body GLAMOS said on Thursday.

The one-two punch for Swiss glaciers during the country's third hottest summer on record means they lost as much ice in two years as in the three decades before 1990, it said, describing the losses as "catastrophic."

"This year was very problematic for glaciers because there was really little snow in winter, and the summer was very warm," Matthias Huss, who leads Glacier Monitoring Switzerland (GLAMOS), told Reuters.

"The combination of these two factors is the worst that can happen to glaciers."

More than half of the glaciers in the Alps are in Switzerland, where temperatures are rising by around twice the global average due to climate change.

This year, low winter snowfall combined with an early start and a late end to the summer melt season dealt the heavy losses, GLAMOS said.

In the peak melt month of August, the Swiss weather service said the elevation at which precipitation freezes hit a new record overnight high, measured at 5,289 meters, an altitude higher than Mont Blanc's summit. This exceeded last year's record of 5,184 meters.

Pictures posted by Huss on social media during data collection trips in recent weeks showed for the first time on record new lakes forming next to glacier tongues, streams of melt water running through ice caves, and bare rock poking out from thinning ice. In some places, bodies lost long ago have been recovered as ice sheets have shrunk.

"We are really losing the small glaciers," Huss said. "The remnant ice is becoming covered by rocks and debris, regions that have been snow and ice covered over the last decades and centuries are becoming just black slopes that are dangerous because of rockfall."

In some places, GLAMOS had to cease monitoring due to the melt.

"We have closed down one of our monitoring programs on a small glacier in central Switzerland because it just became too dangerous to measure," Huss said. "It became very small and therefore unrepresentative."

Swiss records go back to at least 1960 and as far back as 1914 for some glaciers.

(Cover: An aerial photograph shows insulating foam covering a part of the Rhone Glacier to prevent it from melting in the Swiss Alps, August 24, 2023. /CFP)