2018: An Exceptional Year of Losses for Swiss Glaciers

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.

Swiss glaciers: Findelen Glacier 2018 on GlacierHub
The Findelen Glacier, in the Monte Rosa region of southern Valais, Switzerland. Only glaciers at the highest altitudes (over 2000m) had snow thickness losses of less than one meter (Source: Matthias Huss/Swiss Academy of Sciences).

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.

Swiss glaciers: rivers of glacial melt at Findelen Glacier 2018 on GlacierHub
On the Findelen Glacier, even above 3000m elevation, rivers of glacial melt flowed well into September (Source: Matthias Huss/Swiss Academy of Sciences).

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.

Swiss glaciers: Pizol Glacier in 2006 and 2018 reveals massive glacial retreat on GlacierHub
A comparison of the Pizol Glacier in 2006 to 2018, revealing massive glacial retreat and ice covered in debris (Source: Matthias Huss/Swiss Academy of Sciences).

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.

Swiss glaciers: Lake at the tongue of the Rhone Glacier on GlacierHub
The Rhone Glacier developed a lake at its tongue again in 2018, due to the exceptional melting (Source: Matthias Huss/Swiss Academy of Sciences).

“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.”

Please follow, share and like us:

Toxic Algal Blooms: Expert Adaptors to Climate Change

Most people think of algae as the bothersome green stuff that grows on the tops of ponds and needs to be removed from the inside of fish tanks, but algae also provides clues about the environment. The response of Harmful Algal Blooms (HABs) to climate change, for example, provides evidence that some algae are extremely efficient environmental adaptors.

HABs are formed when colonies of algae living in fresh or saltwater grow out of control and begin producing toxic effects that can threaten the health and lives of animals and humans. According to NOAA, they have occurred in every coastal state in the United States and are increasing in frequency due to rising temperatures associated with climate change. As a result, HAB responses to climate change, including changes in pH and CO2, have been increasingly studied.

These responses include the expansion of the blooms into larger areas and an increased release of toxic poisons with warming temperatures. In a recently published paper, Mardones et al examine a special type of algal bloom found to be an expert adaptor to climate change. This strain of algal blooms called Alexandrium catenella occurs in highly variable fjord systems in southern Chile. 

These Chilean fjords have had to respond to fluctuations in CO2 and pH. They experience huge freshwater inputs from Patagonian ice fields and heavy precipitation events. When dissolved in water, CO2 forms carbonic acid, which has a low pH. Therefore, levels of CO2 and pH are inversely correlated. As CO2 increases due to climate change, algal blooms in the fjords produce more Paralytic Shellfish Toxin (PST). This toxin could have long-term effects on the fish population and therefore the entire food web and ecosystem in the fjord.

In an article by Pedro Costa, he describes how these neurotoxins can have a lasting impact: poisoned fish can be consumed by seals and humans, causing health issues or even death. As we expect CO2 to continue to rise, it is very likely harmful algal blooms like the ones in Chile will produce more PST, leading to more fish kills, disturbed ecosystems in the fjords, and possible human health issues.

A view of a Chilean fjord (Source: Wikimedia Commons)

During their research, Mardones et al explored six levels of CO2/pH and two light conditions to examine how the algal blooms react. The scientists identified key differences in the waters in the fjord closest to the melting ice fields and the waters in the fjord further offshore. The near-shore water in the fjord experiences the largest impact of the freshwater inputs from the ice fields. The freshwater means that the upper layers of the water are much less salty compared to lower layers. This creates an intense halocline (stronger layers of differences in salinity) in the water column.  Strong winds in the region mix the layers, which produce highly fluctuating differences in carbonate chemistry. As Patagonian glaciers continue to melt, even more freshwater will be introduced into the fjords, which will continue to change the conditions of the water.  

On the other hand, the more stable offshore waters have CO2 equilibrium with the atmosphere. The main environmental driver offshore is human-caused ocean acidification. As CO2 emissions increase in the atmosphere, it dissolves in oceans and lowers the pH of the water. For most species, this causes huge problems, but certain types of algal blooms are able to adapt to these conditions.

Previous studies done by Tatter et al. show that a type of the same algal bloom from Southern California have previously changed their physiological responses due to changing pCO2/pH. Under higher CO2 conditions, production of Paralytic Shellfish Toxin increased. In 2015, there was an unprecedentedly large algal bloom that stretched from Central California to the Alaskan peninsula.

An aerial shot of a toxic algal bloom (Source: Wikimedia Commons)

Mardones et al. found similar results in the Chilean algal blooms by examining the strains of the bloom under lab conditions. The blooms had been previously harvested years before and kept in culture. They analyzed these HAB responses to changes in pH and CO2. While they had optimal physiological performance at near-equilibrium levels of pH/CO2, the algal blooms showed an ability to adapt to changing conditions. They found that the blooms are in fact able to adapt their cell size based on the pH/ CO2 levels. In conditions with high pH/low CO2, the blooms adapted to a smaller cell size. In conditions with low pH/high CO2, their cell size increased, which means they are able to change their shape to not only survive changing conditions, but to thrive in them. In low CO2, high pH could increase chain formation (they could increase their swim speed to maintain their location without being moved in the current).

These factors, in addition to others, contribute to the resiliency of the harmful algal blooms in changing conditions, demonstrating they are expert adaptors to climate change.

Please follow, share and like us: