At an altitude of 5,100m (17,000ft), where winter temperatures can fall to -40C, it is hard to believe anyone or anything can survive. The vast ice desert of the Changthang plateau, situated between the Himalayan and Karakoram mountain ranges, is the highest permanently inhabited plateau in the world and home to an extremely hardy and rare breed of goat: the Changra.

The altitude, freezing temperatures and harsh bitter winds in this unforgiving mountainous region stimulate the growth of the goats’ supersoft undercoat. The fibres measure a mere 8-10 microns in width, making it about 10 times finer than human hair and eight times warmer than sheep wool. This luxurious fibre is known the world over as pashmina, the softest and most expensive type of cashmere wool in the world.

A yak caravan winds its way up and down the steep valleys. Nowadays, vehicles are used to transport the heavy and bulky items, but with freezing oil and no four-wheel drive, they are no match for a yak.

Rearing these valuable animals in such inhospitable conditions are the Changpa nomads. For centuries these nomadic shepherds, who are as hardy as their animals, have roamed “the roof of the world”, moving their herds of yak, sheep and goats along traditional migratory routes in this high altitude desert every few months in search of fresh grazing pastures.

Changra goats are perfectly at home in the high mountains but when heavy snow falls and freezes hard, their food becomes difficult to reach. To prevent this, they are given food supplements.

Cashmere is expensive and rightly so. The Changpa carefully comb the goats’ hair during the spring moulting season to harvest the downy undercoat and then the good fibre is laboriously separated from the bad by hand. Once cleaned and processed, the wool from a single cashmere goat only amounts to a mere four ounces. After the fibres are manually sorted, cleaned and hand-spun, the weaving process can begin, which is equally demanding and painstaking.

It takes several months to a year for highly skilled artisans to work their magic on wooden looms and weave a masterpiece, which will be exported around the world and sold for up to $2,000 (£1,500) by luxury retailers.

A herder undertakes the time-consuming job of separating the corse outer hair from the finer, softer undercoat. Changpa women, who have given up the nomadic herding life, spend much of their time weaving.

This ancient way of life is now very much under threat. Nomads and scientists alike believe climate change is the biggest threat to pashmina production in the region. The Changthang plateau does not usually get much snowfall, and if it does, it begins in January or February.

However, for the past few years it has been increasingly heavy, starting as early as December or even November. Food supplements have to be brought in to prevent the animals dying from starvation. Winters have also been getting warmer, which has reduced the quality and quantity of the valuable pashmina wool.

Many of the elders still wear their traditional dress, which is considerably warmer that modern clothes. The Changpa do not actually wear cashmere, simply because it is too valuable.

Over a relatively short period of time, dozens of nomad families from the village of Kharnak in the Changthang plateau have migrated away to set up their own neighbourhood called Kharnak Ling on the outskirts of Leh city, 180km away.

“These are worrying times we are experiencing,” says the Kharnak village chief. “If weather patterns continue like they are then it could have an irreversible impact on pashmina goat-rearing on the Changthang.

“There were once more than 90 families in Kharnak and now there are only 16,” he adds. “If the number of Changpa families in Kharnak falls below 10 then life will become too tough for us to continue this life. The younger generation would rather work in the city and cannot be persuaded to continue this physically, mentally and emotionally demanding existence.”

India’s Textile Ministry is now trying to help reverse the trend before it is too late. It is providing $1.2m for winter fodder and 50 animals to each herder as a way of encouraging the Changpa to return to rearing goats on the plateau.

In recent years, due to a lack of cashmere wool from Ladakhi herders, weavers in Kashmir have begun importing raw Pashmina from China and Mongolia to meet ever-increasing demand. Much of this pashmina is not what it is claimed to be; the goats at not reared in the extreme conditions required to stimulate the growth of the supersoft undercoat to be officially classified as 100% pure pashmina. Ladakh produces less than 1% of the world’s total raw cashmere, but it is renowned for being the finest in the world.

Due to the decreasing numbers of this rare Himalayan goat and increasing demand for genuine cashmere from the Ladakh region of Kashmir, scientists at the University of Kashmir decided to create the world’s first cloned pashmina goat. The project, partly funded by the World Bank but mostly by the Indian government, was successful, and on 9 March 2012 the female kid Noori was born.

The scientists had planned to share their goat-cloning knowledge across the Himalayas to help others grow their own goats. However, this has not gone down well with the Changpa herders in the region, primarily because of their Buddhist beliefs.

Each family has several hundred goats, all of which need to be moved separately so that they don’t get mixed up.

The threat to pashmina goat-rearing would not only mean the end of the livelihoods of about 300,000 people in the Jammu and Kashmir state who, directly or indirectly, depend on pashmina, but would also mean an end to the unique culture of the Changpa; most of them are followers of Tibetan Buddhism and have an elaborate set of customs centred around their livestock.