The treasured 'eternal snow' on this tropical island is about to disappear forever

Image source, Project Pressure/Klaus Tymann Image caption, Only small patches of snow remain on Papua's Sudirman Range

The mountains of Papua are not far from the equator, but they've been topped with "eternal snow" for centuries.

The peaks in this Indonesian region on the world's second-largest island, just north of Australia, have offered scientists countless insights into the Earth's climate history.

They're also the epicentre of the spiritual universe for many Papuans - a Mecca or a Vatican, as one activist puts it.

A century ago, the 300km (190-mile) stretch of the Sudirman Range had snow and permanent ice on all four of its major peaks.

But now there are only small areas around Puncak Jaya, also known as Carstensz Pyramid, with any snow at all. These are expected to entirely disappear in a year or two.