In 2018, Swiss glaciers lost over 2.5 percent of their overall volume, reported the Swiss Academy of Sciences in a recent press release. This corresponds to 1.4 billion cubic meters of ice that melted from Switzerland’s glaciers in just one year.
However, this year of exceptional melting actually began with a rather promising winter season. The 2017-2018 winter commenced earlier than expected in Switzerland, starting in the first days of November and continuing through December with reported snowfall above average levels. January also saw higher temperatures than normal, as well increased precipitation.
While snow depth below 1000m elevation was around half the expected average by January, snow above 2000m elevation was still twice the expected average in March, representing the highest snow levels seen in the past 20 years.
GlacierHub interviewed the author of the press release, Matthias Huss, who said, “After the winter measurements in April and May, we actually thought that this might be a good year for the glaciers at last.” Huss is also the leader of the Swiss Glacier Monitoring Network (GLAMOS) and a glaciologist at the Swiss Federal Institute of Technology Zurich, Switzerland.
However, both April and May were hot and dry, decreasing snow at altitude to relatively normal levels. Then, the months from April to September were characterized by drought conditions and high temperatures, making it the third-hottest and overall driest summer on record.
“This is probably the largest annual shrinkage since the mega-heatwave of 2003,” said Martin Beniston, an honorary professor and former director of the Institute for Environmental Sciences at the University of Geneva, Switzerland, in an interview with GlacierHub.
Both Beniston and Huss told GlacierHub that, had it not been for this snow-rich winter, Switzerland’s glaciers would have faced even more extreme losses. Indeed, the above-average quantities of snow in the Alps during winter 2017-2018 helped offset some loss of ice this summer.
In an interview with GlacierHub, Mauri Pelto, a glaciologist at Nichols College and the director of the North Cascades Glacier Climate Project commented on the implications of 2018’s extreme melting. “The significance of a big year of melt followed by another is there will be no comparable rebound,” he said.
Wilfried Haeberli, a glaciologist and professor emeritus at the University of Zurich, Switzerland, put this year’s loss in perspective. “Since the turn of the century the average loss rate of all glaciers in the Alps can be estimated at around 1-2 percent per year. The loss rate of 2018 is roughly twice this amount,” he noted in an interview with GlacierHub. Together in the last 10 years, Swiss glaciers have lost one-fifth of their volume, which is enough to cover the entirety of Switzerland with 25 cm of water.
While certainly extreme, losing 2.5 percent of glacial volume in one year is not unprecedented. Years with observations of “extreme” glacier melt are becoming both more frequent and more severe. Huss recalled the years 2015 and 2017, when Swiss glaciers lost comparable amounts of ice, saying, “2018 was not absolutely exceptional, in terms of the last decade. And this is of course the actually worrying news.”
Pelto, Beniston, and Haeberli echoed similar sentiments, saying that the observed losses for Swiss glaciers were, “exceptional but not unusual,” and that 2018 was, “hardly a surprise,” but instead, “part of a long-term development, which is in agreement with robust results from model simulations about global warming and glacier vanishing,” respectively.
On a global scale, glaciated areas in several other countries saw noticeably higher snowlines and rapid volume loss due to melting in 2018. Some notable examples of this widespread glacial retreat include: the Lowell Glacier in Yukon, Canada; the Taku Glacier in Alaska, U.S.; the Chubda, Angge, and Bailang Glaciers along the Bhutan-China border; and the Inostrantsev and Pavlova Glaciers in Novaya Zemlya, off the coast of northern Russia.
“The fact that high snowlines and mass balance loss are affecting glaciers in every corner of the world indicates that this is not a regional change, but that global climate change is the driver,” said Pelto.
Huss also pointed out the difficulty of deducing whether extreme conditions in the past few years is due to weather variability, or whether we are to experience these extremes as our new normal. However, noting that the volume loss for Swiss glaciers in the past decade was more than expected based on projected scenarios for the 21st century, he is certain that, “if it is the latter, then we might expect Swiss glaciers to disappear even earlier than expected.”
According to Beniston, since the 3rd Assessment Report of the IPCC in 2001, projections have estimated that at the current rate of climate change, glaciers will decline by anywhere from 50 to 90 percent by 2100. “[This year] provides a measure of things to come,” he said, “in the sense that by the second half of the 21st century, what are considered extreme summers today (like 2018) will become average summers.”
Ultimately, Haeberli told GlacierHub he sees these striking glacier mass losses as “writing on the wall,” indicating that opportunities for action to reduce impacts of global warming are now being lost. He closed his comments by calling upon the necessity of “rapid deceleration” of greenhouse gas emissions in order to limit negative effects on living conditions on Earth and allow us more time to “develop well-reflected sustainable adaptation strategies.”