- Researchers calculated that the glaciers have lost around 40% of their area
- Glaciers shrank from a peak of 28,000 square km to around 19,600 square km
- The team used satellite images and digital elevation models
London: Glaciers in the Himalayas are melting at an “exceptional” rate because of global warming, threatening the water supply of millions of people in Asia, according to a study published on Monday (December 20). The researchers found that the Himalayan glaciers have lost ice ten times more quickly over the last few decades than on average since the last major glacier expansion 400-700 years ago, a period known as the Little Ice Age. The study, published in the journal Scientific Reports, also shows that Himalayan glaciers are shrinking far more rapidly than glaciers in other parts of the world.
Also Read: South Asia Faces Environmental Watershed Amid Climate Change: Experts
A team led by researchers at the University of Leeds, UK, made a reconstruction of the size and ice surfaces of 14,798 Himalayan glaciers during the Little Ice Age.
They calculated that the glaciers have lost around 40 per cent of their area — shrinking from a peak of 28,000 square kilometres (km2) to around 19,600 km2 today.
During that period they have also lost between 390 cubic kilometres (km3) and 586 km3 of ice, the researchers said.
The water released through that melting has raised sea levels across the world by between 0.92 millimetres (mm) and 1.38 mm, they said.
“Our findings clearly show that ice is now being lost from Himalayan glaciers at a rate that is at least ten times higher than the average rate over past centuries,” said study corresponding author Jonathan Carrivick, from the University of Leeds.
This acceleration in the rate of loss has only emerged within the last few decades, and coincides with human-induced climate change, Mr Carrivick said.
Also Read: UN’s Weather Agency Confirms 2020 Arctic Heat Record At 38°C
The Himalayan mountain range is home to the world’s third-largest amount of glacier ice, after Antarctica and the Arctic and is often referred to as ‘the Third Pole’.
The acceleration of melting of Himalayan glaciers has significant implications for hundreds of millions of people who depend on Asia’s major river systems for food and energy, the researchers said.
These rivers include the Brahmaputra, Ganges and Indus, they said.
The team used satellite images and digital elevation models to produce outlines of the glaciers’ extent 400-700 years ago and to ‘reconstruct’ the ice surface.
The satellite images revealed ridges that mark the former glacier boundaries and the researchers used the geometry of these ridges to estimate the former glacier extent and ice surface elevation.
Comparing the glacier reconstruction to the glacier now, determined the volume and hence mass loss between the Little Ice Age and now.
The Himalayan glaciers are generally losing mass faster in the eastern regions — taking in east Nepal and Bhutan north of the main divide.
Also Read: US Climate Envoy Kerry Says China, India, Russia Must Do More To Tackle Warming
The study suggests this variation is probably due to differences in geographical features on the two sides of the mountain range and their interaction with the atmosphere — resulting in different weather patterns.
Himalayan glaciers are also declining faster where they end in lakes, which have several warming effects, rather than where they end on land, the researchers said.
The number and size of these lakes are increasing so continued acceleration in mass loss can be expected, they said.
Glaciers which have significant amounts of natural debris upon their surfaces are also losing mass more quickly, contributing around 46.5 per cent of total volume loss despite making up only around 7.5 per cent of the total number of glaciers.
While we must act urgently to reduce and mitigate the impact of human-made climate change on the glaciers and meltwater-fed rivers, the modelling of that impact on glaciers must also take account of the role of factors such as lakes and debris, Mr Carrivick added.
Also Read: Study Reveals Arctic Ocean Started Getting Warmer Decades Earlier Than Expected
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)
NDTV – Dettol have been working towards a clean and healthy India since 2014 via Banega Swachh India initiative, which is helmed by Campaign Ambassador Amitabh Bachchan. The campaign aims to highlight the inter-dependency of humans and the environment, and of humans on one another with the focus on One Health, One Planet, One Future – Leaving No One Behind. It stresses on the need to take care of, and consider, everyone’s health in India – especially vulnerable communities – the LGBTQ population, indigenous people, India’s different tribes, ethnic and linguistic minorities, people with disabilities, migrants, geographically remote populations, gender and sexual minorities. In wake of the current COVID-19 pandemic, the need for WASH (Water, Sanitation and Hygiene) is reaffirmed as handwashing is one of the ways to prevent Coronavirus infection and other diseases. The campaign will continue to raise awareness on the same along with focussing on the importance of nutrition and healthcare for women and children, fight malnutrition, mental wellbeing, self care, science and health, adolescent health & gender awareness. Along with the health of people, the campaign has realised the need to also take care of the health of the eco-system. Our environment is fragile due to human activity, that is not only over-exploiting available resources, but also generating immense pollution as a result of using and extracting those resources. The imbalance has also led to immense biodiversity loss that has caused one of the biggest threats to human survival – climate change. It has now been described as a “code red for humanity.” The campaign will continue to cover issues like air pollution, waste management, plastic ban, manual scavenging and sanitation workers and menstrual hygiene. Banega Swasth India will also be taking forward the dream of Swasth Bharat, the campaign feels that only a Swachh or clean India where toilets are used and open defecation free (ODF) status achieved as part of the Swachh Bharat Abhiyan launched by Prime Minister Narendra Modi in 2014, can eradicate diseases like diahorrea and the country can become a Swasth or healthy India.