Longevity of Bhutan’s glaciers questionable

Though the 2035 Himalayan deadline was deemed wrong, the same can’t be said for the ones here 

Symposium: Bigger Himalayan glaciers, like Siachen and Gangotri in India, can survive 300 years even with the current recession rate of 20m on an average a year, according to experts from the Geological Survey of India (GSI).

But that is no consolation for Bhutan.

The director, glaciology division of the GSI, Arun Chaturvedi, at the recent international glacier symposium at Ugyen Wangchuck Institute for Conservation and Environment in Bumthang, said the same could not be said about glaciers in Bhutan.

The director said it was unlikely that Himalayan glaciers would be gone by 2035, as erroneously predicted by the Intergovernmental Panel on Climate Change (IPCC) in 2007. “But given the glaciers changing at variable rates across Himalayas and the globe, it can’t be precisely said if glaciers in Bhutan can survive that long,” he said.

“We can’t really say if the smaller glaciers in the Bhutanese Himalayas will survive that long, because of its greater response to factors, such as temperatures and rainfall,” Arun Chaturvedi said.

GSI director general Harbans Singh said glaciers behave differently in different places because of numerous factors, such as shade, exposure to sun, slope and snowfall.

“No one can really precisely say how long glaciers in Bhutan will survive unless a study is conducted,” Harbans Singh said.

But what cannot be denied is that most of the glaciers are actually retreating.

“Except for glaciers in Karakoram and those in the Western Himalayas, most of the glaciers in the Eastern Himalayas are receding,” Arun Chaturvedi said.

Bhutan, sandwiched in the eastern Himalayas, is host to 885 glaciers.  Earlier, a report from International Centre for Integrated Mountain Development (ICIMOD) stated that Bhutan has lost 23.3 percent of its glacier area between 1980 and 2010.  ICIMOD also found that the number of glaciers in Bhutan increased by 14.8 percent, because of shrinking and fragmentation of glaciers between 1980 and 2010.

“Glaciers at elevations below 5,600m above sea level are melting much faster,” the ICIMOD findings stated.

Mountain glaciers in the monsoonal Himalayas showed highest rates of retreat in recent years, Professor Joerge Schaefer, from Columbia University, USA, said.

According to findings based on reconstruction of glacier fluctuations in last 2000 years in the Himalayas, Bhutan’s glaciers are shrinking, but its melt water, which is rising now, could deplete in the future.

“Glaciers in Bhutan are in the bull’s eye of the temperature sensitivity,” Joerge Schaefer said.

He said Bhutan’s sustainable development required robust prediction of ongoing and future glacier change for hydropower, GLOF mitigation and conservation.

But limited studies on the Himalayan glaciers, and the controversy and limitations surrounding the glacier melt, are hindering such predictions, GLOF mitigation and conservation efforts, Joerge Schaefer said.

It is indicated that the glaciers in Bhutan have never melted as fast as now from summer warming on the millennial scale, according to conservation projections of Columbia University, on glacier area and melt water flux changes.

“In fact, our quantitative estimate shows that the highly responsive glaciers of Bhutan have been and are going to be outpaced by the effects of warming temperature in the region,” Joerge Schaefer said.

It means, even if the global warming were to come to an immediate halt, glaciers in Bhutan would continue to shrink for years, reducing melt water reservoir contribution for surface runoffs to rivers.

“Glaciers in Bhutan need to be understood on various time-scales, but our first results indicate that our holistic approach might afford for calibrating a glacier model to apply towards robust predictions of glacier change,” Joerge Schaefer said.

Meanwhile, Arun Chaturvedi also said it was unlikely that the receding glaciers in the Himalayas would ever return as before.

“Because for the first in hundreds of years, carbon concentration, which stood at 280 ppm during the industrial revolution in Europe, has been bridged by today’s 393 ppm,” Arun Chaturvedi said.

Unless, man changed the source of energy and fuel, it was unlikely that glaciers would ever come back, he said.

By Tempa Wangdi, Bumthang

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