Pakistan and India's military standoff in the frozen high mountains of Kashmir is not only costing soldiers' lives, experts say -- it is also wreaking havoc on the environment.

A huge avalanche on Saturday devastated Pakistan's Gayari army camp on the fringes of the Siachen Glacier, where Pakistani and Indian soldiers brave bitter conditions to eyeball each other in a long-running territorial dispute.

Environmental experts say the heavy military presence is speeding up the melting of the glacier, one of the world's largest outside the polar regions, and leaching poisonous materials into the Indus river system.

Faisal Nadeem Gorchani of the Sustainable Development Policy Institute in Islamabad said the glacier had shrunk by 10 kilometres (six miles) in the last 35 years.

"More than half of the glacier reduction comes from the military presence," he said.

Pakistani hydrologist and Siachen specialist Arshad Abbasi gave an even more alarming assessment of the glacier's decline, and said that non-militarised areas had not suffered so badly.

"More than 30 percent of the glacier has melted since 1984, while most of the Karakoram glaciers on the Pakistani side expanded," he said.

Troop movements, training exercises and building infrastructure all accelerate melting, Gorchani said.

Waste from the military camps is also a major problem, harming the local environment and threatening to pollute the water systems that millions of people across the subcontinent depend upon.

"Indian army officials have described the Siachen as 'the world's biggest and highest garbage dump'," US expert Neal Kemkar said in an article for the Stanford Environmental Law Journal.

The report quoted estimates from the International Union for Conservation of Nature saying that on the Indian side alone, more than 900 kilos (2,000 pounds) of human waste was dropped into crevasses every day.

Kemkar said that 40 percent of the military waste was plastics and metal, and as there are no natural biodegrading agents present, "metals and plastics simply merge with the glacier as permanent pollutants, leaching toxins like cobalt, cadmium, and chromium into the ice."

"This waste eventually reaches the Indus River, affecting drinking and irrigation water that millions of people downstream from the Siachen, both Indian and Pakistani, depend upon," the report said.

Kemkar also warned the conflict had affected wildlife, with the habitat of animals such as the endangered snow leopard, the brown bear and the ibex -- a type of wild goat -- all threatened.

There is virtually no chance of any of the 138 people buried by Saturday's avalanche being found alive, so they will likely be added to the list of those claimed by Siachen, dubbed "the world's highest battleground", with outposts more than 6,000 metres high.

An estimated 8,000 troops have died in the glacier's freezing wastes since conflict over the area flared in 1984.

Colonel Sher Khan, a retired Pakistani officer and mountain expert, says that not a single shot has been fired in anger in at least eight years and combat deaths in Siachen have numbered only in the dozens.

The rest have succumbed to frostbite, altitude sickness, heart failure and inadequate cold weather equipment -- as well as avalanches and landslides.

Military experts quoted in local media say a Pakistani soldier dies around every three or four days in Siachen, and the latest disaster has led to louder calls for a negotiated end to the standoff, particularly given the huge expense of maintaining troops at such a high altitude.

The cost of the operation is kept under wraps but Pakistani daily newspaper The News reported that Pakistan spends $60 million a year on Siachen and India more than $200 million.

In two countries where millions live below the poverty line this is a lot of money to defend an frozen, uninhabitable patch of mountain, but after nearly 30 years of stalemate, no-one is expecting a swift end to the dispute.

"It's a matter of ego. Nobody is ready to take that step, even if they want it, because elections are coming," said retired colonel Khan.

The soldiers facing each other across the icy, inhospitable mountain wastes have one thing in common, at least.

"India and Pakistan are not fighting each other in Siachen, they are both fighting the glacier, and nature takes its revenge by killing soldiers," said Abbasi.