More than twice as much global glacier mass will remain if countries restrict temperature rise to 1.5 degrees Celsius, compared to the warming level of 2.7 degrees Celsius resulting from the current policies, says a new study released.
Glaciers are even more sensitive to global warming than previously estimated, and, if the world warms to 2.7 degrees Celsius compared to the pre-industrial levels, only 24 per cent of the present-day glacier mass will remain in contrast to preserving 54 per cent by limiting warming to 1.5 degrees Celsius, the study published in ‘Science’ suggests.
“These figures, however, are global, skewed mostly by the very large glaciers around Antarctica and Greenland. The glacier regions most important to human communities are even more sensitive, with several losing nearly all glacier ice already at 2 degrees Celsius,” a press release from the International Centre for Integrated Mountain Development (ICIMOD) here says, quoting the study.
These results come amid growing concern regarding the impacts of glacier and snowpack loss by world leaders as the first global UN conference focused on glaciers opens in Dushanbe, Tajikistan on Friday, with the participation of officials from over 50 countries.
Glaciers are a perennial source of water and are very sensitive to the changing climate. Scientists define mass balance as the difference between snow accumulated in winter and the loss of snow and ice in summer. Knowing or calculating mass balance is critical as it is a direct indicator of total water availability for any given glacier.
The Hindu Kush Himalaya—where glaciers feed river basins supporting 2 billion people across eight countries, including India and Nepal—shows only 25 per cent of 2020 ice levels remaining at 2 degrees Celsius, warns the study.
“Staying close to 1.5 degrees Celsius on the other hand preserves at least some glacier ice in all regions, even Scandinavia, with 20-30 per cent remaining in the four most sensitive regions; and 40-45 per cent in the Himalayas and Caucasus,” pointed out the study.
The study stresses the growing urgency of the 1.5 degrees Celsius temperature goal and rapid de-carbonisation to achieve it.
Under the 2015 Paris Agreement, more than 180 countries agreed to cut down on emissions to restrict temperature rise to well below 2 degrees Celsius and to pursue efforts to limit warming to 1.5 degrees Celsius by 2100 above pre-industrial levels (1850–1900).
The study also mentions glaciers of the European Alps, the Rockies of the Western US and Canada, and Iceland, with only 10-15 per cent of their 2020 ice levels remaining at 2 degrees Celsius sustained warming. “Most hard-hit will be Scandinavia, with no glacier ice remaining at all at 2 degrees Celsius,” says the study.
To get these results, a team of 21 scientists from 10 countries used eight glacier models to calculate the potential ice loss of more than 2,00,000 glaciers worldwide, under a wide range of global temperature scenarios, according to the study.
“In all scenarios, the glaciers lose mass rapidly over decades and then continue to melt at a slower pace for centuries, even without further warming,” the study points out. “This means they will feel the impact of today’s heat for a long time before settling into a new balance as they retreat to higher altitudes.”
“Our study makes it painfully clear that every fraction of a degree matters,” remarked co-lead author Dr Harry Zekollari from the Vrije Universiteit Brussel. “The choices we make today will resonate for centuries, determining how much of our glaciers can be preserved.”
“Glaciers are good indicators of climate change because their retreat allows us to see with our own eyes how climate is changing… but the situation for glaciers is actually far worse than visible in the mountains today,” warns co-lead author Dr Lilian Schuster from the University of Innsbruck.
According to a five-year forecast released Wednesday, there is an 80 per cent chance the world will break another annual temperature record in the next five years.
“And it’s even more probable that the world will again exceed the international temperature threshold set 10 years ago,” the forecast by the World Meteorological Organisation (WMO) and the UK Meteorological Office says.
Earlier in the month, speaking at a high-level dialogue on mountains and glaciers—named the Sagarmatha Dialogues to honour Mt Everest or Sagarmatha in Nepali—Nepal’s Prime Minister K P Sharma Oli said: “Mountains may seem far away. But their breath keeps half the world alive.”
“From the Arctic to the Andes, from the Alps to the Himalayas – they are the Earth’s water towers… and they are in danger.” (Agencies)
