The Candid Eye

November 28, 2009

Global warming effect on Himalayan glaciers!!

An official discussion paper on the status of Himalayan glaciers is coming under fire. The paper, issued recently by the Ministry of Environment and Forests, argued that the glaciers, which nourish several great rivers such as the Indus, Ganges and Brahmaputra, have not retreated abnormally. It also questioned the link between climate change and the glaciers’ decline.

Releasing the paper, the Union Minister of State for Environment and Forests, Mr. Jairam Ramesh, remarked that there was no conclusive evidence to show that global warming was responsible for the glacial retreat.

 

Himalayan Glaciers : Image Courtesy - http://www.nsf.gov

Contradictory views

Such views completely contradict the findings of the Intergovernmental Panel on Climate Change (IPCC), the Nobel-Prize-winning international body of scientists that weighs up the scientific evidence. Two years back, the IPCC released its comprehensive Fourth Assessment Report on Climate Change.

The report pointed out that glaciers and ice caps provided the most visible indications of the effects of climate change. The Himalayan glaciers were receding faster than in any other part of the world.

If these glaciers continued to recede at the present rate, there was a very high risk of their disappearing by the year 2035, perhaps sooner, if the earth kept warming at the current rate.

Biggest threat

It warned that water scarcity, which could affect more than a billion people, was the most serious threat that Asia faced from climate change.

The Ministry’s riposte has been prepared by V.K. Raina, a retired Deputy Director-General of the Geological Survey of India. In the discussion paper, he agreed that glaciers in the Himalayas, barring a few exceptions, have been in constant retreat since observations started in the mid-Nineteenth Century. Moreover, studies showed all glaciers under observation to have lost mass during the last three decades of the last century.

However, “Himalayan glaciers, although shrinking in volume and constantly showing a retreating front, have not in any way exhibited, especially in recent years, an abnormal annual retreat of the order that some glaciers in Alaska and Greenland are reported [to have shown].” It would be premature to state that these glaciers were retreating abnormally because of global warming.

Glacier movements are primarily due to climate and snowfall. But then Mr. Raina goes on to state that movements of the ’snout’, the visible end of a glacier, “appear to be peculiar to each particular glacier.” The Gangotri glacier, which fed the Ganges River, was practically at a standstill for the last two years.

Rajendra Pachauri, chairman of the IPCC, has criticised both the discussion paper and the Minister. He did not understand why the Minister was supporting such unsubstantiated research, he told the Guardian newspaper.

The discussion paper was unscientific and biased, said Syed Iqbal Hasnain, a leading glaciologist who is currently with The Energy and Resources Institute (TERI) in New Delhi. It had ignored scientific papers published in peer-reviewed journals after the 1980s when the impact of long-lived greenhouse gases became more visible. These papers clearly showed that warming of the climate was leading to the Himalayan glaciers melting at an exceptionally high rate, he said in an email.

The discussion paper had been sent to him a month back by the Minister’s office for review and he had responded with detailed comments. He had also provided the Minister with all recent papers published by Indians in peer-reviewed journals on the subject. But the paper had been unfortunately been released without any change.

Short-lived pollutants

Himalayan glaciers were not only affected by long-lived greenhouse gases like carbon dioxide but also by short-lived pollutants like black carbon, methane and atmospheric ozone, according to Prof. Hasnain.

In the eastern part of the Himalayas, the excessive melting of glaciers had led to lakes being formed in Nepal, Sikkim and Bhutan, remarked Shresth Tayal, another glaciologist at TERI.

Just recently, the prestigious science journal Nature carried a report on how the mountain kingdom of Bhutan was trying to drain such glacial lakes. Otherwise these lakes might burst their embankment and flood neighbouring areas.

In a paper that appeared in the journal Current Science in 2001, geologists from the HNB Garhwal University in Uttarakhand pointed out that the Gangotri glacier had retreated by two kilometres in the past 200 years. Over 40 per cent of that retreat had occurred in just the last 25 years.

Satellite images

A group led by scientists at the Indian space agency’s Space Applications Centre in Ahmedabad used satellite images to study 466 glaciers in the Chenab, Parbati and Baspa basins.

They found that the glaciers had shrunk by 21 per cent since 1962. The glaciers had also become more fragmented, which was likely to profoundly influence their sustainability, said Anil Kulkarni and others in a 2007 paper.

In recently published research, the space scientists used a model to study how loss of glaciers could affect water flow in a tributary of the Sutlej River.

They estimated that a one degree Celsius rise in temperature by 2040 would more than halve the area occupied by the glaciers that fed the tributary. The runoff in the tributary could therefore come down by between eight per cent and 28 per cent, depending on the season.

Source : The Hindu

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