Glaciologists, geologists on Monday said that sweeping statements regarding the environmental impact on the Himalayan glaciers cannot be made before long term comprehensive study is carried out.
They were reacting to the controversy relating to the reports that Himalayan glaciers will melt by 2035.
Director (Glaciology Division) Geological Survey of India CV Sangewar told HT from Lucknow, "The date of melting of even the smallest glacier cannot be pointed out because the response time of glacier to the weather parameter and inter-action with the glacier body requires number of studies including heat balance and mass balance studies."
One has to undertake these studies for a long term period sometimes 50-100 years and then also the year of melting can only be an estimation within a span of a decade, he added.
"The GSI studies so far have not indicated any alarming rate of the recession of the Himalayan glaciers," he said.
Number of studies have been undertaken to estimate the impact of climate change on the glaciers but the studies are at a micro level than macro level, he said.
"One has cover the entire Himalayas and all its different climatic zones to get a comprehensive picture which has not been done so far."
There are 9575 glaciers in the Indian part of the Himalayas and "we have 100 year study from 1906 onwards (intermittently) of only 40 glaciers. The data of these glaciers suggests that there is no alarming rate of recession or shrinkage of glaciers and it continues to remain at a normal rate which is between 5 to 25 metres per year."
Glaciologist DP Dhobal from Wadia Institute of Himalayan Geology, Dehradun told HT, "Glaciers are not disappearing by 2035. Our limited study of 10 years shows 15 to 20 metres recession which is not considered alarming, many of these glaciers are also receding at much lower rate of 5 to 7 metres per year and some are not receding at all. I was unable to trace even though I tried, wherefrom the date 2035 emanated."
A study group was formed in 2008 to compile all available information on Himalayan glaciers by the Principal Scientific Advisor to Government of India Chidambaram.
Chairperson of the study group Dr Anand Patwardhan told HT from Mumbai, "Climate is one of the factors that will effect glacier response but one cannot conclude about glacier response only on the basis of projected climate."
"Our report on many different glacier parameters such as recession, mass balance, palaeo climate for cross comparison and other analysis will be submitted this week which will prove a useful source of information for trends and patterns of change of glaciers," he added.
The glacier formation is a dynamic process and a sustained and systematic method has to be adopted to understand the process .We are at the stage of building the empirical data and we cannot do any prediction and projection unless we have modeled the entire glacier system, he added.
Geologist at Physical Research Laboratory, Ahmedabad, Navin Juyal said there is no "scientific basis" for the date 2035, "it is a sensational story.. . has sex appeal". "It has been "cricised in many scientific forums", he added.
He said there is a fine line between statement of scientist and scientific statement which is peer reviewed and based on research.
Some glaciers are showing recessionary trends but then some others in Karakoram area are showing advancement in view of that it is difficult to give an unequivocal statement."It is not wise to give a general blanket statement saying that glaciers will disappear by 2035," he added.
M Prithviraj, scientist dealing with Glaciology at the Department of Science and Technology, said, "It is only after 50 to 100 years of continuous recording of data regarding the glacier can one come to some conclusion regarding when it will melt. This very long term monitoring we have not done in the country like some European countries."