Narrow, but over 4,000 kilometres long, Chile is home to 4% of the world’s and 80% of South America’s glaciers. Located in the Andes mountain range, they provide a vitally important water resource but are under threat from global warming.

The host country of the UN’s COP25 international climate talks, Chile is working on a new inventory of its glaciers. With only half of the assessment carried out, the outlook is already worrying.

Except for three, all of the glaciers inventoried in Chile are retreating. Many have fragmented, which further accelerates melting. Along with climate change, industrial activities like mining pose big threats.

In this context, Chilean congress is debating a law to protect glaciers. If approved, it would make the country only the second in the world, after Argentina, to have such regulations.

Calculation in process

A glacier is a zone of compacted ice that grows more each winter than it shrinks in summer and is constantly moving under its own weight. If this ceases to be the case, the remains are known as ‘dead ice’.” Despite being home to so many glaciers, Chile’s knowledge of them is poor.

“We do not know exactly how many ice masses we have, nor what actual volume they are,” said Francisco Ferrando, a geographer at the University of Chile.

Except for three, all of the glaciers inventoried in Chile are retreating. Halfway into the survey, 24,000 glaciers, with an average area of one hectare, have been inventoried.

Extreme fragmentation makes monitoring difficult since ice masses are often too small for satellites to detect.

“In Chile we have a relatively moderate temperature increase due to the strong influence of the Pacific Ocean. But in mountainous areas that is not the case and that’s where the glaciers are located,” said Gino Casassa, head of the Glaciology and Snow Unit at Chile’s National Water Directorate.

The unique geography of the country makes monitoring difficult. Glaciers are mostly found in the north and centre of the country, but also in the southern region of Patagonia.