Argentina’s Perito Moreno glacier undergoing fastest retreat in century

The Perito Moreno Glacier in Argentina, long considered one of the few glaciers on Earth to remain stable despite global warming, is now experiencing its “most substantial retreat in the past century,” according to new research.

The glacier, part of the Southern Patagonian Ice Field, has for decades been securely wedged in a valley. But scientists say it has begun losing contact with the bedrock beneath it, causing it to shed more ice as it inches backward.

A series of dramatic time-lapse photographs taken since 2020 illustrates the change, which study authors describe as showing “the fragile balance of one of the most well-known glaciers worldwide.” The research, published in Communications Earth & Environment, warns that Perito Moreno is expected to retreat several more kilometres in the coming years.

“We believe that the retreat that we are seeing now, and why it is so extreme in terms of values that we can observe, is because it hasn’t been climatically stable for a while now, for over a decade,” said Moritz Koch, a doctoral student at the Friedrich-Alexander University of Erlangen-Nuremberg and one of the study’s authors. “Now we see this very delayed response to climate change as it is slowly but surely detaching from this physical pinning point in the central part of the glacier.”

Koch and his team collected their data through extensive fieldwork, measuring ice thickness from a helicopter equipped with radar, conducting sonar surveys on the lake, and analysing satellite images.

Difficult to predict glacial collapse

Every year, hundreds of thousands of people visit Glaciar Perito Moreno, a UNESCO World Heritage Site since 1981, to witness large ice chunks “calve” into Lake Argentino.

“The basic physics of climate change and glaciers is intuitive: heat melts ice, and global warming means more and faster glacial melting,” said Richard Alley, an ice scientist at Pennsylvania State University who was not involved in the research. “But much like a dropped coffee mug, it's harder to predict when and exactly how they're going to break apart.”

Alley noted that climate change sceptics have often cited Perito Moreno’s stability as evidence against global warming, despite the fact that glaciers naturally fluctuate.

Erin Pettit, a glaciologist at Oregon State University who also was not involved in the study, said that without climate change, natural cycles of snow and ice accumulation would generally offset melting.

Why melting glaciers matter

Glacial retreat, especially in polar regions, could drive catastrophic sea level rise, threatening millions in coastal and island communities. Alley said studies like this one are critical to understanding “what might happen to the big guys” in Antarctica.

Beyond global implications, glaciers also play vital roles in local environments and cultures. Pettit noted that glaciers shape landscapes, serve as freshwater sources, and can cause devastating mudslides when they collapse.

“We are losing these little bits of ice everywhere,” Pettit said. “Hopefully we’re slowly gaining more respect for the ice that was here, even if it's not always there.”

By Sabina Mammadli