A TOP climate scientist has warned that a warm early summer combined with a heatwave last week may have caused severe glacier melt in Switzerland, threatening to make 2023 its second-worst year for ice loss after a record thaw last year.

Matthias Huss of the Glamos glacier monitoring centre said that full data would not be in until late September and a precipitous drop in temperatures and high-altitude snowfall in recent days could help stem any more damage.

But early signs based on readings from five sites and modelling results across Switzerland suggest that considerable damage may already be done.

“We can definitely say that we had very high melting in Switzerland and in Europe in general because the temperatures. They were extremely high for a long time — a more than one-week heatwave,” Mr Huss said in an interview this week.

Swiss meteorologists reported last week that the zero-degree Celsius level had risen to its highest altitude since recordings of it in Switzerland began nearly 70 years ago, meaning that all of the country’s mountains faced temperatures above freezing.

The late-summer heatwave was particularly harmful to glaciers this year because high temperatures earlier in the summer had already melted nearly all of the protective snow cover, which meant that “almost all glacier ice was kind of naked,” Mr Huss said.

A blanket of white snow cover protects glaciers by reflecting energy from sunlight back upward, a process known as the albedo effect.

Switzerland’s estimated 1,400 glaciers, which serve as a bellwether for the impacts of climate change, had a historically punishing year in 2022.

“We’re definitely not going to beat the records of last year … but right now, it seems that we’re on track to be maybe the second-most negative year,” Mr Huss said.

A combination of factors made for a near-perfect storm in 2022, including low winter snow cover, warm temperatures in early summer, greater heat later in that season and weather patterns that carried orange-coloured dust from the Sahara desert up to Switzerland — colouring the snow and ice.

A staggering 6 per cent of glacier volume in Switzerland was lost in that single year.

“For comparison, we lost, on average, about 2 per cent in the last decade and already 2 per cent is very high,” said Mr Huss.

“If you extrapolate that, that would tell you that in 50 years we have nothing left. If we lose 6 per cent in one year, it’s much more extreme.”

Strong melting and glacier disappearance in recent years has already caused Mr Huss’s team to halt three of its 20 monitoring programmes that take detailed measurements.

This year, one was ended at the Saint Annafirn glacier, south of the central village of Andermatt, because measurements there were no longer meaningful, he said.

“The glacier is so small by now, and dangerous, because it has receded so much that there is a lot of rock fall,” he said.

With areas such as the town of Zermatt, at the foot of the Matterhorn, hitting 31°C last week, the impacts will continue to be felt.

“We can say it’s climate change that makes these years with very strong melting much more likely,” said Mr Huss.

“In the last decades, I would say that almost every year is kind of an extreme year.”