“`html
Matthias Huss recalls his initial encounter with Switzerland’s Rhône Glacier 35 years ago, when the ice was a mere stroll from his family’s parked car.
“Stepping onto the ice for the first time evoked a profound sense of timelessness,” states Huss.
Today, reaching the glacier from the same spot requires a half-hour trek, a stark contrast to the past.
“Each return visit serves as a reminder of its former state,” reflects Huss, now the director of Glacier Monitoring in Switzerland (GLAMOS), “and the glacier’s appearance during my childhood.”
This narrative resonates with numerous glaciers globally, as these frozen rivers are experiencing a rapid retreat.
According to a recent World Meteorological Organization report, glaciers excluding the major ice sheets of Greenland and Antarctica shed 450 billion tonnes of ice in 2024.
This volume equates to a colossal ice block measuring 7km in height, width, and depth – enough water to fill 180 million Olympic-sized swimming pools.
“Glaciers worldwide are undergoing melting,” explains Prof. Ben Marzeion of the University of Bremen’s Institute of Geography. “They exist in a climate that has become increasingly hostile due to global warming.”
GLAMOS data released this week reveals that Switzerland’s glaciers have been particularly affected, losing a quarter of their ice mass in the past decade.
“The sheer scale of this melting is truly difficult to comprehend,” notes Dr. Huss.
However, visual evidence from both satellite and ground-level perspectives paints a clear picture.
Satellite imagery illustrates the transformation of the Rhône Glacier since Dr. Huss’s initial visit in 1990, revealing a lake where ice once dominated.
Until recently, glaciologists in the Alps considered an annual ice loss of 2% to be an “extreme” occurrence.
However, 2022 shattered this benchmark, with Switzerland’s remaining ice volume diminishing by nearly 6% in a single year.
Significant losses have persisted in 2023, 2024, and continuing into 2025.
Regine Hock, professor of glaciology at the University of Oslo, has observed the Alps since the 1970s.
She describes the changes witnessed throughout her lifetime as “truly striking,” emphasizing that “the changes we are seeing now are massive and occurring within just a few years.”
The Clariden Glacier, located in northeastern Switzerland, maintained a relatively stable balance until the late 20th century, with snowfall gains roughly equaling melting losses.
However, this century has brought about rapid melting.
For numerous smaller glaciers, such as the Pizol Glacier in the northeastern Swiss Alps, the change has been irreversible.
“This is a glacier I once observed, and now it’s completely gone,” says Dr. Huss. “It definitely makes me sad.”
Photographic records provide insights into the more distant past.
The Gries Glacier, situated in southern Switzerland near the Italian border, has retreated by approximately 2.2km (1.4 miles) over the past century. A large glacial lake now occupies the area where the glacier’s terminus once stood.
In southeastern Switzerland, the Pers Glacier once fed the larger Morteratsch Glacier, which descends towards the valley. The two glaciers are now disconnected.
Moreover, the Alps’ largest glacier, the Great Aletsch, has receded by approximately 2.3km (1.4 miles) over the past 75 years. Trees now populate the area formerly covered by ice.
Glacier expansion and contraction are natural processes that have occurred for millions of years.
During the colder periods of the 17th, 18th, and 19th centuries, known as the Little Ice Age, glaciers regularly advanced.
During this era, many were viewed with superstition in Alpine folklore, their advances attributed to malevolent forces as they encroached upon villages and farmland.
Tales even recount villagers summoning priests to appease the spirits of the glaciers and implore them to retreat further up the mountain.
Glaciers began their widespread retreat across the Alps around 1850, though the timing varied regionally.
This period coincided with the rise of industrialization, when the burning of fossil fuels, particularly coal, began to warm the atmosphere. However, distinguishing between natural and human-induced causes so far in the past remains challenging.
There is little doubt, however, that the accelerated losses observed over the past 40 years are primarily attributable to human activity.
Absent human-induced global warming – driven by the burning of fossil fuels and the release of substantial amounts of carbon dioxide (CO2) – glaciers would likely be relatively stable.
“We can only fully account for the observed changes by considering CO2 emissions,” affirms Prof. Marzeion.
Adding to the concern is the fact that these massive bodies of ice require decades to fully respond to the rapidly warming climate. This means that even if global temperatures stabilized immediately, glaciers would continue to recede.
“A significant portion of future glacial melt is already inevitable,” explains Prof. Marzeion. “Glaciers are lagging behind climate change.”
However, there is still reason for hope.
Research published this year in the journal Science indicates that limiting global warming to 1.5C above pre-industrial levels (late 1800s) could preserve half of the remaining ice in the world’s mountain glaciers.
Current projections point towards a warming of approximately 2.7C above pre-industrial levels by the end of this century, potentially resulting in the eventual loss of three-quarters of the world’s glaciers.
The resulting increase in water flowing into rivers and ultimately the oceans will contribute to rising sea levels, posing a threat to coastal populations worldwide.
However, mountain communities that rely on glaciers for freshwater will be particularly vulnerable to the loss of ice.
Glaciers function as natural reservoirs, storing water as snowfall that transforms into ice during colder, wetter periods and releasing it as meltwater during warmer periods.
This meltwater plays a crucial role in stabilizing river flows during hot, dry summers – at least until the glacier disappears.
The loss of this vital water resource will have cascading effects on all those who depend on glaciers for irrigation, drinking water, hydropower, and even shipping.
While Switzerland faces its own challenges, the implications are far more profound for the high mountain regions of Asia, sometimes referred to as the Third Pole due to their extensive ice reserves.
An estimated 800 million people rely, at least in part, on meltwater from glaciers in this region, particularly for agricultural purposes. This includes the upper Indus River basin, which serves parts of China, India, Pakistan, and Afghanistan.
In regions with drier summers, meltwater from ice and snow may be the only significant source of water for months at a time.
“That’s where we see the greatest vulnerability,” says Prof. Hock.
What are the emotions experienced by scientists as they contemplate the future prospects of glaciers in a warming world?
“It’s disheartening,” says Prof. Hock. “But at the same time, it’s also empowering. By decarbonizing and reducing our [carbon] footprint, we can preserve glaciers.”
“The power to do so is in our hands.”
Top image: Tschierva Glacier, Swiss Alps, in 1935 and 2022. Credit: swisstopo and VAW Glaciology, ETH Zurich.
Additional reporting by Dominic Bailey and Erwan Rivault.
Sign up for our Future Earth newsletter to keep up with the latest climate and environment stories with the BBC’s Justin Rowlatt. Outside the UK? Sign up to our international newsletter here.
The Conservative leader says net zero targets are “destroying more jobs than they’re creating”.
Sarah Adams’ hunt for inaccessible locations often requires a kayak, as well as a brush and easel.
Fifteen projects are shortlisted for a chance of winning the top £1m prizes at next month’s environmental awards ceremony in Rio de Janeiro.
Residents are being encouraged to increase nature in their communities and protect the environment.
This local take on the hit 3D video game aims to inform children about things like coastal erosion.
“`