For centuries, the balance of melting glaciers in the Himalayas has provided for a stable and secure source of water for millions of people in Asia. And, for this reason, the thinning and reduction of these ice masses is of great concern to people in the region.
The question in this context appears to be one wondering about: what will happen when the glaciers disappear?
The Intergovernmental Panel on Climate Change (IPCC), for example, makes global estimates in which it believes that 80% of the world’s glaciers could disappear by the end of this century, in a high-emissions scenario.
In the view of the uncertainty at the local level, a group of experts decided to analyse the retreat rates in the Himalayas, on a centennial time scale.
The results, published in the journal “Nature”, show that glaciers have reached a melting rate 10 times higher than 700 years ago in recent decades.
Glaciers Are Melting At A Rapid Rate
In other words, this rate of thawing has caused at least 40% of the frost cover to be lost over the past 400 years. As is usual in this type of work, they warn that these changes are not homogeneous i.e., there are areas where the setback is “disproportionate.”
Thus, Nepal, which only has 16% of the glaciers, has contributed to 35% of the total loss of ice volume. It is also to be noted that Nepal is a young country that is still building its infrastructural and other kinds of capabilities.
“The Himalayan glaciers covered about 28,000 square kilometers at their maximum, while today this extension has been reduced to approximately 19,500 square km”, the authors emphasise.
During that time, the Himalayas have also lost between 390-586 cubic km of ice: he equivalent of all that is found today in the Alps of central Europe, the mountains of the Caucasus—between Armenia, Azerbaijan, and Georgia—and Scandinavia. Together.
Human-Induced Climate Change
They also point out that they decrease faster where they converge in large lakes, since these masses help to melt ice much faster than when the glacier settles on land, due to water temperatures above zero degrees Celsius.
A similar effect is currently being experienced by the Thwaites glacier.
“It is the local topography and glaciological attributes such as debris cover and the presence of a proglacial lake, that promote rapid mass loss,” the authors observed.
“This acceleration in the rate of loss has occurred in recent decades and coincides with human-induced climate change,” added Jonathan Carrivick, lead author of the study and deputy director of the School of Geography, at the University of Leeds.
Keeping An Eye On The Future (Loss)
Finally, the authors have compared these rates with those recorded in other glaciers around the world, concluding that the response in the Himalayas is the “most spectacular” anywhere on the globe.
“Overall, quantifying past glacier variability on a centennial time scale, should help validate numerical models of climate and glaciers, and thus, produce more reliable projections of future mass loss,” the experts concluded.
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The writer is a journalist based in Jammu and Kashmir. He writes about environment-related issues, climate Change in South Asia, and is a media fellow with NFI India. He can be reached at bwahid32@gmail.com; Twitter: @Wahidbhat32