The Himalayan glaciers, which serve as water reservoirs for nearly two billion people in South Asia, have changed dramatically in recent decades, threatening water supplies and security for the entire world. Indian subcontinent. The glaciers of the Kashmir Himalayas, in particular, are melting at an alarming rate.

Scientists have found that glaciers in the Himalayan region of northwest Kashmir are disappearing at a faster rate than in other regions of the Himalayan Arc. Using satellite data, field photographs and ground observations, a study published in September showed that Kashmir’s Machoi Glacier lost 29% of its size between 1972 and 2019.

Researchers in the study at the University of Kashmir noted that retreating glaciers can have a significant effect on river flow patterns, hydropower production, and agricultural production in the region.

“Based on the comparison with previous work done on nearby glaciers in the western Himalayan region, Machoi is the fourth highest area of ​​glacial retreat at 0.66% per year,” the researchers wrote.

Associated article:

  • Will the song of nature resonate?

The Machoi Glacier is located in the Dras region of northwest Kashmir, stretching between 3,762 m and 5,050 m above sea level. It is close to the Srinagar-Kargil highway, exposing the glacier to traffic pollution and other emissions.

The study showed that Machoi is vulnerable to cryoconite holes. Cryoconite is a powder made up of rock particles, soot and microbes. When it lands on a glacier, the soot melts some of the ice, creating a hole in the surface of the glacier. Aerosols, unburned carbon particles, and other debris build up in this hole over time and accelerate melting. “Microbial life, which can survive in these environments, also releases heat which contributes to melting,” the research said.

Researchers have found that Machoi is a moderately receding glacier with recession rates between the rapidly melting Himalayan glaciers of Kashmir and the slowly receding Zanskar Glacier Group among masses of ice that end on dry land. .

These results, while disturbing, are not surprising. Previous research has also found that almost all of the Indus glaciers, which include the Kashmir glaciers, are receding rapidly.

Giants that shrink

A 2020 study mapped 147 glaciers in the Kashmir region from 1980 to 2018, tracking the effects of topography, morphology, and climate. According to the report, glaciers have shrunk by 28.82% during this period, and the loss of glaciers in the region is considerably greater than in other Himalayan regions.

Kashmir’s Kolahoi Glacier, the largest glacier in the Himalayas, has lost nearly 23% of its area and fractured into smaller sections since 1962. Several adjacent small glaciers have disappeared. The Kolahoi Glacier has shrunk to about 11.5 square kilometers, up from about 13 square kilometers over the past 40 years.

Kolahoi’s meltwater makes the Kashmir Valley fertile for the production of grains, fruits which are then dried, saffron and apples. Kolahoi feeds two main tributaries of the Jhelum River. The rapid recession of this major glacier directly threatens the livelihoods of millions of people living downstream.

Associated article:

  • The inventor who changed the lives of Indian farmers

Outside of the Arctic and Antarctic, the vast Himalayan region of the Hindu Kush, from northeast India to Afghanistan, holds the largest concentration of snow and frozen water on Earth. third pole ”. Almost 15,000 Himalayan glaciers, including 3,136 in the mountainous belt of Jammu and Kashmir, constitute a unique reservoir that supplies perennial rivers such as the Indus, Ganges, Brahmaputra and Mekong, providing drinking water and the agricultural needs of large sections of the population living in the Indo-Gangetic plains.

Studies have concluded that the main drivers of accelerated glacier retreat are increased temperature and decreased snowfall. Research has shown that temperature increases in the Himalayan region have been between 0.15 ° C and 0.6 ° C per decade, which is far above the average rate of global warming.

Floods and landslides

The latest study by the Intergovernmental Panel on Climate Change (IPCC), published in August, warns that more changes are expected for the Himalayas. The analysis predicts that seasonal snowfall length, ice mass and permafrost area will continue to decline by mid-century. Snow-covered areas and snow volumes will decrease in most sections of the Hindu Kush Himalayas, while glacier volumes are likely to decrease with greater mass loss under carbon dioxide emission scenarios. higher carbon.

Poor seasonal snow cover, loss of summer arctic sea ice, and melting of glaciers and ice caps will be exacerbated by further increases in global temperature. The IPCC report predicts that over the next decades, climate change will increase in all regions. With a 1.5 ° C increase in global temperature, there will be increasing heat waves and longer hot seasons. With an increase of 2 ° C, extreme heat would more often reach critical tolerances for agriculture and health, according to the report.

A 2019 report from the International Center for Integrated Mountain Development concluded that glaciers in the Himalayan region of the Hindu Kush could lose more than a third of their volume by 2100, even if the world manages to maintain the global warming below 1.5 ° C. Since the 1970s, almost 15% of the ice has disappeared. In the short term, glaciers in the Himalayan region are expected to lose 10-30% of their mass by 2030. This number is expected to rise to 25-35% by 2050.

Associated article:

  • Long read | Climate resilience in the Caribbean

As the snow melts faster, the Himalayas are increasingly marked by lakes. According to a report, nearly 900 new glacier-fed lakes emerged in the high mountains of Asia between 1990 and 2010.

When glaciers melt, water in glacial lakes collects behind loose, natural “glacial / morainal dams” made of ice, sand, pebbles and ice residue. As these mountain lakes fill with additional sleet and the moraines can no longer hold up, what scientists call glacial lake flooding can occur. These flash floods pose a huge risk to infrastructure and life downstream.

In February of this year, part of the Nanda Devi Glacier broke away in the state of Uttarakhand, northern India, inundating the Dhauliganga River and causing large-scale devastation in the upper parts of the Himalayas. ecologically fragile. Dozens of people have been killed. In 2013, a similar flash flood caused by the eruption of a glacial lake also in Uttarakhand killed at least 5,700 people and left unprecedented damage and destruction.

A study sponsored by the United Nations in 2008, Concrete mountains: construction of dams in the Himalayas, predicts dramatic declines in inputs to the Indus basin over the next 100 years. The study warned of extreme changes in river flows due to global warming. “As glaciers melt, river water will increase and dams would be subject to much higher flows, raising concerns about dam safety, increased flooding and submersion. And with the ensuing glacier depletion, there would be much lower annual flows, affecting the performance of dams built with huge investments, ”the study notes.

Irregular water supply

Melting glaciers and the associated effects interfere with the activities of people who depend on their waters. The South Asian region is already experiencing faster snowmelt, warmer winter temperatures and heavier rains, leading to frequent flooding and landslides, soil erosion, and a build-up of debris and soil. silt. Crops are damaged, fruits ripen too early, and agricultural insects and diseases are increasingly common.

Those who depend on the huge rivers that flow from the Himalayas to India, Pakistan, China and other countries will suffer immediate and dire consequences. The billions of people living downstream from the Himalayas will be affected by an increasingly unreliable and erratic water supply. Less intense snowfall, for example, has already delayed grass production in the prairies, altering herd movements, especially yak migration. The growing seasons are shorter than in the past, which affects crops and the social life of farmers.

Associated article:

  • When farmers reap the bitter fruits of climate change

According to a recent BBC report on a village of Kumik in India’s northern Ladakh region, shrinking glaciers due to global warming have triggered a severe water shortage in the area, forcing some people to abandon their homes. and to migrate.

Another threat to glaciers is the overcrowding of environmentally sensitive areas, as India, Pakistan and China, which share the Himalayan ranges of the Hindu Kush, continue to promote religious tourism, construction projects and facilities. military.

If you would like to republish this article, please read our guidelines.


Source link