Two-thirds of Himalayan glaciers could melt, study warns




  • In Science
  • 2019-02-04 17:50:08Z
  • By Paavan MATHEMA
Glaciers in the Hindu Kush-Himalayas region are a critical water source for more than a billion people
Glaciers in the Hindu Kush-Himalayas region are a critical water source for more than a billion people  

Kathmandu (AFP) - Two-thirds of Himalayan glaciers, the world's "Third Pole", could melt by 2100 if global emissions are not sharply reduced, scientists warned in a major new study issued Monday.

Even if the most ambitious Paris Agreement goal of limiting global warming to 1.5 degrees Celsius (2.7 degrees Fahrenheit) is achieved, one-third of the glaciers would go, according to the Hindu Kush Himalaya Assessment.

Glaciers in the Hindu Kush-Himalaya (HKH) region are a critical water source for some 250 million people in the mountains as well as to 1.65 billion others in the river valleys below, the report said.

The glaciers feed 10 of the world's most important river systems, including the Ganges, Indus, Yellow, Mekong and Irrawaddy, and directly or indirectly supply billions of people with food, energy, clean air and income.

Impacts on people from their melting will range from worsened air pollution to more extreme weather.

Lower pre-monsoon river flows will throw urban water systems and food and energy production off-kilter, the study warned.

Five years in the making, the 650-page report was published by the International Centre for Integrated Mountain Development (ICIMOD) in Nepal, one of eight countries on the front line.

More than 350 researchers and policy experts, 185 organisations, 210 authors, 20 editors and 125 external reviewers contributed to its completion.

"Global warming is on track to transform the frigid, glacier-covered mountain peaks... cutting across eight countries to bare rocks in a little less than a century," Philippus Wester of ICIMOD said in a statement.

"This is the climate crisis you haven't heard of."

- Thinning, retreating -

The 2015 Paris Agreement vowed to cap global warming "well below" two degrees Celsius above pre-industrial levels, and to pursue efforts to limit the temperature increase to 1.5 degrees Celsius.

In December, the UN climate forum agreed on a common rule book to implement the accord, but failed to deliver fresh commitments to reduce planet-warming greenhouse gases.

Voluntary pledges currently in place would see Earth heat up by more than 3C, a recipe for widespread human misery, say scientists.

The new report notes that a 1.5C increase in global temperatures would mean a rise of at least 2.1C in the Himalayas region. If emissions continue unabated, the roof of the world would warm by an unlivable 5C.

"This is a landmark piece of work," commented Jemma Wadham, a professor of glaciology at the University of Bristol in England who did not contribute to the report.

"The discovery that a third of the Himalayan glaciers could disappear signals potentially disastrous consequences for river flows, pollution and managing natural hazards associated with extreme events for more than one billion people."

The Himalayan glaciers, which formed some 70 million years ago, are highly sensitive to changing temperatures. Since the 1970s, they have thinned and retreated, and the area covered by snow and snowfall has sharply decreased.

As the glaciers shrink, hundreds of risky glacial lakes can burst and unleash floods.

Satellite data shows that numbers of such lakes in the region grew to 4,260 in a decade from 3,350 in 1990.

"Emerging hazards -- in particular glacial lake development and increasingly unstable rock and ice faces -- will become a major concern," said Duncan Quincey, an associate professor at the University of Leeds school of geography.

Air pollution from the Indo-Gangetic Plains -- one of the world's most polluted regions -- also deposits black carbon and dust on the glaciers, hastening melting and changing monsoon circulation, the ICIMOD study said.

The region would require up to $4.6 billion per year by 2030 to adapt to climate change, rising to as much as $7.8 billion per year by 2050, according to an estimate in the report.

"Without the ice reserve in the mountains to top up the rivers through the melt season, droughts will be harsher on those living downstream," noted Hamish Pritchard, an expert on ice dynamics at the British Antarctic Survey, commenting on the findings.

COMMENTS

More Related News

In degrading Nature humanity harms itself, UN report warns
In degrading Nature humanity harms itself, UN report warns

Diplomats and scientists from 130 nations gather in Paris next week to vet and validate the first UN global assessment of the state of Nature in more than a decade, and the news is not good. A quarter of 100,000 species already assessed are on a path to extinction, and the total number facing a forced exit from the world stage is closer to a million, according to an executive summary, obtained by AFP, of a 1,800-page scientific report three years in the making. A score of 10-year targets adopted in 2010 under the UN's biodiversity treaty -- to expand protected areas, slow species and forest loss, and reduce pollution impact -- will almost all fail, the draft Summary for Policy Makers...

Why sea creatures are fleeing their homes
Why sea creatures are fleeing their homes

There are 3,800 big thermometers floating in the ocean, and the readings don't lie: Over 90 percent of the warming created by humans is soaked up by the seas. Unsurprisingly, many creatures are feeling the heat. In new research published Wednesday in the journal Nature, scientists found that global warming has forced twice as many marine species than land species to vanish from their hotter habitats --particularly near the already balmy equator. All the species examined were cold-blooded, or ectotherms."What we found so surprising is that global warming hits sea creatures the hardest," said Malin Pinsky, an evolutionary ecologist at Rutgers University and lead author of the...

A new Stanford study shows the economic cost of climate change is more global inequality
A new Stanford study shows the economic cost of climate change is more global inequality

The economic gap between the world's poorest and richest countries is 25% larger because of global warming, a new Stanford study shows.

One million species risk extinction due to humans: draft UN report
One million species risk extinction due to humans: draft UN report

Up to one million species face extinction due to human influence, according to a draft UN report obtained by AFP that painstakingly catalogues how humanity has undermined the natural resources upon which its very survival depends. The accelerating loss of clean air, drinkable water, CO2-absorbing forests, pollinating insects, protein-rich fish and storm-blocking mangroves -- to name but a few of the dwindling services rendered by Nature -- poses no less of a threat than climate change, says the report, set to be unveiled May 6. Indeed, biodiversity loss and global warming are closely linked, according to the 44-page Summary for Policy Makers, which distills a 1,800-page UN assessment of...

Leave a Comment

Your email address will not be published. Required fields are marked with *

Cancel reply

Comments

Top News: Science

facebook
Hit "Like"
Don't miss any important news
Thanks, you don't need to show me this anymore.