Swiss glaciers suffered what reports call a disastrous loss of ice after a run of intense summer heat.

The Swiss Academy of Sciences said extreme temperatures sped the melt and raised concern about water supplies.

Stations reported that more than 5 percent of total glacier volume disappeared in a single record summer.

Scientists said a drop that steep had not been expected for decades.

About 20 percent of Switzerland’s glacier mass has gone since the middle of the last decade, the article says.

Millions of people in Europe rely on that ice for farm water, drinking water, and hydropower.

The piece warns that smaller glaciers increase the risk of seasonal shortages and arguments over shared rivers.

Read the full story on Switzerland’s glacier loss and the water-supply consequences.