Puncak Jaya’s shrinking glaciers put a climate record and sacred landscape at risk

Only small patches of snow and ice remain around Puncak Jaya in Indonesia’s Papua region, according to a BBC report published on 25 September. Their retreat threatens both a record of the region’s climate and a mountain landscape with deep spiritual meaning for Indigenous communities. A separate satellite study measured just 0.165 square kilometres of glacier area in 2024, underscoring how little ice was left even before the BBC’s latest account.

The BBC reported that permanent ice once covered all four major peaks along the 300-kilometre Sudirman Range. It now survives only in small areas around Puncak Jaya, also known as Carstensz Pyramid. The report describes a landscape that has changed within living memory, while researchers are trying to document the remnants before they disappear.

What the measurements show

In a study published in The Cryosphere in December 2025, David Ibel, Thomas Mölg and Christian Sommer used high-resolution satellite images from 2023 and 2024 alongside historical maps to assess the glaciers’ area. They estimated 0.165 square kilometres of glacier ice in 2024, with an uncertainty of 5%. That figure describes the area measured in 2024; it is not a measurement of the ice remaining in September 2026.

The study found that total glacier area had fallen by more than 99% since 1850 and by about 65% since a 2018 survey. Its long historical comparison and more recent satellite measurements both point to substantial retreat. The researchers said the glaciers would very likely disappear around 2030 if the current rate of area loss continues. That forecast depends on future retreat following the measured trend, so it does not establish a date when the last ice will vanish.

A disappearing climate archive

Glacier ecologist Marie Šabacká told the BBC that Papua’s tropical glaciers are unusual because thousands of kilometres separate them from other glacier systems. Ice cores taken from Puncak Jaya preserve evidence of past atmospheric conditions in a region surrounded by the tropical Pacific and the Western Pacific Warm Pool. Their loss would remove material scientists can use to investigate the region’s climate history.

The Cryosphere study describes Puncak Jaya’s ice as the only remaining tropical glaciers in the West Pacific Warm Pool. It also explains why this is a difficult place to study: the glaciers are remote, and few direct measurements of their thickness and mass have been made. The researchers used satellite imagery to close a gap since earlier surveys and to place recent changes alongside historical records.

Šabacká attributed the retreat to a warming atmosphere driven by human activity, including the burning of fossil fuels. She told the BBC that warming raises the altitude at which precipitation freezes, so places that once received snow may increasingly receive rain. El Niño events can accelerate the loss, she said, while cloud cover, snowfall and the shape of the mountains also affect its pace. Those influences help explain why the remaining ice cannot be given a certain expiry date.

What the mountain means locally

For Amungme people interviewed by the BBC, the mountain’s changing appearance carries a meaning beyond its scientific value. They know the range as Nemangkawi, or the ‘White Arrow’. Elfrida Natkime said parents and grandparents invoked the White Arrow when teaching children to follow the proper path. She described it as a symbol of honesty, purity and moral integrity.

Amungme environmental activist Adolfina Kum compared the loss of Nemangkawi with damage to a sacred centre of another faith. She told the BBC that when sacred mountains, forests or ancestral places are disturbed, communities lose an important source of strength. Her account makes clear why a change measured in square kilometres can also be experienced as a loss of cultural continuity.

The BBC also reported that industrial development around Papua’s mineral deposits has changed parts of the surrounding landscape. Papuans described jobs, roads and education alongside environmental damage, social conflict and loss of access to ancestral land. Natkime acknowledged livelihoods provided by development while expressing sadness about exploitation. The BBC said it had sought comment from Freeport, operator of the Grasberg mine; no response appeared in its report. The glacier study does not assess mining as a cause of ice retreat.

The precise area of ice remaining today has not been established by the 2024 satellite measurement. What is documented is the scale of the long-term decline, Thymann’s account of continued retreat through 2025, and the BBC’s report of small patches still visible in 2026. Researchers can continue to document the remaining ice, but the study’s disappearance estimate remains conditional on the pace of retreat ahead.