High in Indonesia's Papua region, where the mountains rise just 450 kilometres south of the equator, a rare tropical ice world is nearing its end. For centuries, the peaks of the Sudirman Range carried snow and permanent ice, a startling contradiction in one of the planet's warmest regions. Today, only small patches remain around Puncak Jaya, also known as Carstensz Pyramid, and scientists say those last remnants are expected to vanish within a year or two.
What is disappearing is more than a scenic curiosity. The glaciers of Papua have long served as a natural archive of Earth's climate history, preserving ice cores that can reveal information about atmospheric conditions and the changing behaviour of the tropical Pacific and the Western Pacific Warm Pool. But the record is being erased faster than researchers can fully study it. Glacier cover around Puncak Jaya has shrunk from nearly 1,900 hectares in the 19th century to about 16 hectares today, a collapse so dramatic that almost entire glaciers have vanished within a human lifetime.
"There is a profound unfairness in this," said Marie Šabacká, a Czech glacier ecologist who travelled to Puncak Jaya last March in an effort to be among the last scientists to examine Papua's "eternal snow." She described the tropical glaciers as unique because they are isolated from other glacier systems by thousands of kilometres, making them the last remaining tropical ice between the Andes and the Himalayas. Their disappearance, she said, removes both a biological habitat and part of a culturally significant landscape.
The retreat is part of a global pattern, but in Papua the speed and symbolism of the loss are especially acute. Šabacká said the glaciers are shrinking because of a warming atmosphere driven by human activity, including the burning of fossil fuels such as coal, oil and gas. As temperatures rise, the freezing point moves higher up the mountains, meaning more precipitation falls as rain rather than snow, even in places that once regularly received snowfall. El Niño events can accelerate the process, while cloud cover, snowfall and mountain topography also shape how quickly the ice disappears.
The mountains' location makes them especially vulnerable. At this latitude, permanent ice can survive only at very high altitudes and within a narrow range of climatic conditions. A small increase in temperature, or a shift from snowfall to rainfall, can be enough to determine whether a glacier survives at all. For scientists, the retreat is not just a local environmental story but proof of a warming planet unfolding over decades.
For many Papuans, however, the loss is also spiritual. At least five Indigenous groups have long held deep ties to Puncak Jaya and the surrounding range. The Moni people call it 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," said Elfrida Natkime, a young Amungme woman. "It symbolises honesty, purity and moral integrity."
For activists and local communities, the vanishing snow is therefore not only an environmental emergency but an erosion of identity and memory. One activist has described the mountain as a spiritual centre comparable to Mecca or the Vatican, underscoring the depth of reverence attached to the peaks. As the last ice retreats, Papua is losing a rare scientific resource, a habitat shaped by millennia of climate history, and a sacred landmark that has anchored Indigenous belief for generations.
The disappearance of Papua's "eternal snow" is expected to be complete soon. When it is gone, the loss will stand as one more visible sign that the climate crisis is not a distant forecast but a present-tense transformation, reaching even the most improbable places on Earth.