The mountains of Papua, positioned just 450 kilometres south of the equator on the world's second-largest island, have been crowned with "eternal snow" for centuries. Yet this frozen legacy is rapidly disappearing. Nearly all the snow that once defined the Sudirman Range has now melted, with only small patches remaining around Puncak Jaya, also known as Carstensz Pyramid. According to Indonesia's meteorological agency, these final remnants are expected to vanish entirely by the end of 2026 or early 2027.
The scale of this transformation is staggering. A century ago, the 300-kilometre stretch of the Sudirman Range maintained snow and permanent ice across all four of its major peaks. Glacier coverage around Puncak Jaya has contracted from nearly 1,900 hectares in the 19th century to approximately 16 hectares today. More dramatically, Indonesian researchers report that the glaciated area has shrunk to just 2 per cent of its 1988 size, with the glacier thickness declining by about 2 to 2.5 metres annually over the past decade. Almost entire glaciers have vanished within a single human lifetime.
The peaks have long offered scientists invaluable insights into Earth's climate history. Ice cores extracted from Puncak Jaya's slopes preserve a detailed record of atmospheric conditions in the region and reveal changes in the planet's warmest ocean waters—the tropical Pacific and Western Pacific Warm Pool—that surround the island. Yet this irreplaceable archive is disappearing before researchers have fully studied it.
Marie Šabacká, a Czech glacier ecologist who travelled to Puncak Jaya in March to be among the last scientists to study Papua's "eternal snow", emphasises the uniqueness of these glaciers.
There is a profound unfairness in this, she says. The tropical glaciers in Papua are separated from other glacier systems by thousands of kilometres, making them home to the "last remaining tropical ice" between the Andes and Himalayas. Research indicates that Papua's tropical glaciers have lost 97 per cent of their ice mass between 1980 and 2024, with four of the six glaciers on the mountain already gone.
What is driving the glacier collapse?
The retreat of Papua's glaciers stems from the same forces affecting ice worldwide: a warming atmosphere caused by human activity, including the burning of fossil fuels such as coal, oil and gas. As temperatures rise, the freezing point shifts higher up mountains, causing more precipitation to fall as rain rather than snow, even in regions that historically experienced regular snowfall. El Niño events can accelerate this process, while local factors including cloud cover, snowfall patterns and mountain topography influence the pace of melting.
The mountains in Papua occupy an exceptionally precarious position. At such proximity to the equator,
permanent ice can survive only at very high altitudes and within a narrow range of climatic conditions, Šabacká explains. A modest increase in temperature, a higher freezing point or a shift from snowfall to rainfall can determine whether a glacier persists at all. The glaciers' retreat serves as evidence that the Earth has been warming over an extended period, and their disappearance removes both a biological habitat and part of a culturally significant landscape.
Why does this matter to Indigenous communities?
At least five groups of Indigenous people have maintained strong spiritual ties to Puncak Jaya for generations. The Moni people refer to it as Mbainggela and believe their ancestors watch over the mountain. To the Amungme people, the range is known as Nemangkawi, or the "White Arrow".
Parents and grandparents prayed their children would have hearts like the White Arrow, never straying from the proper path, says Elfrida Natkime, a young Amungme woman.
It symbolises honesty, purity and moral integrity.
According to traditional Amungme beliefs, Nemangkawi embodies how people should live. Amungme environmental activist Adolfina Kum stresses the peak's profound importance to her people and warns that traditions and cultural foundations risk being shattered as the ice melts.
How would Muslims feel if Mecca were destroyed? How would Catholics feel if Rome or the Vatican were destroyed?she asks.
For the Amungme people, that is what it feels like when Nemangkawi is destroyed.
For many Indigenous Papuans, the glacier's disappearance does not occur in isolation. The discovery of vast copper and gold deposits transformed the region during the 20th century, and the development of extractive industrial projects has reshaped significant portions of the landscape. Entire mountain faces have been excavated and roads, industrial infrastructure and settlements have transformed surrounding valleys. Papuans acknowledge that development has brought jobs, roads, education and economic opportunities, but also environmental degradation and decades of social conflict. Some have lost access to their ancestral lands as mining expanded.
Every time I see the mountains, I feel amazed, but I also feel sadness, says Elfrida Natkime.
Since the company came, I have seen the exploitation. But the development has also provided a livelihood for many people.
Adolfina Kum believes communities
lose an important source of strengthwhen sacred mountains, forests or ancestral places are disturbed.
I often describe it as pulling out the roots of a tree. Once the roots are removed, the tree loses its foundation.
How are scientists documenting what remains?
As local communities watch their sacred landscapes transform, scientists and explorers are racing to document what survives. Using drones and three-dimensional mapping techniques, Danish researcher Klaus Thymann and his team have created a detailed model of the remaining ice. From the early 2000s to 2025, the glaciated area has receded by 95 per cent, he reports.
There's almost no ice left. Those are the facts.
Thymann emphasises that glaciers function as
incredibly powerfulindicators of climate change.
When people hear that something described as 'eternal' is disappearing, it triggers a reaction, he explains. This emotional and scientific resonance has made Papua's vanishing ice a focal point for climate research and advocacy.
What happens next?
The timeline for total disappearance has narrowed considerably. World Meteorological Organization forecasts project total loss of the last tropical glacier by late 2026 or early 2027, though some assessments suggest a broader outer deadline of 2030. The next milestone will be the actual vanishing of the ice itself—an event that will mark the end of an era for both the scientific community and the Indigenous peoples for whom these peaks hold sacred meaning. Once the glaciers disappear, the opportunity to extract climate records from ice cores will be lost forever, and a landscape that has defined spiritual and cultural identity for millennia will be fundamentally transformed.
Key Facts
- Puncak Jaya's glacier coverage has shrunk from nearly 1,900 hectares in the 19th century to approximately 16 hectares today, with the remaining ice expected to vanish by late 2026 or early 2027.
- Papua's tropical glaciers have lost 97 per cent of their ice mass between 1980 and 2024, making them the last tropical ice fields between the Andes and Himalayas.
- At least five Indigenous groups, including the Moni and Amungme peoples, hold deep spiritual connections to Puncak Jaya, viewing it as a sacred anchor for their cultural and moral identity.
- Ice cores from the mountain preserve irreplaceable records of regional atmospheric conditions and changes in the tropical Pacific's warmest ocean waters, a climate archive that will be lost when the glaciers disappear.
- The glacier retreat is driven by rising global temperatures caused by human activity, combined with local factors such as cloud cover, snowfall patterns and mountain topography.
