11 November 2009

Firm in their belief: Himalayan glaciers not retreating 'rapidly'

By: Kaavya Nag

The Ministry of Environment and Forests has recently released a discussion paper reviewing glacial studies and glacial retreat in India. Minister Jairam Ramesh has a clear caveat in the report that the views so expressed are not endorsed by the Union of India, and that it is only mean to ‘stimulate discussion’. Interestingly, India does not have a position on glacier retreat in the Himalayas.

Prepared ex deputy chairman of the Geological Survey of India V.K. Raina, the paper provides a summary of the literature on glacier studies so far, but its main claim to fame is that it challenges internationally accepted views that the Himalayan glaciers are receding due to climate change. It says there is little evidence for the same, and that ‘none of the glaciers under monitoring are recoding abnormal retreat’.

Data from a large proportion of the studies considered in this report indicate that glacier mass balance – a measure of the difference between melting and sublimation – is negative, and that most monitored glaciers have retreated since the earliest records. Nevertheless (and despite credible evidence from around the world and closer home - China, Nepal, Bhutan), concluding remarks suggest ‘glaciers in the Himalayas, 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 note also, is the fact that ‘recent years’ implies 2007-2009 – a period of time that is clearly far too short to come to such sweeping conclusions, particularly on climate-related studies.

While the report suggests that the Sonapani glacier has retreated 500 m in the last century, the Kangriz glacier has ‘practically not retreated even an inch’. These statements however, are not backed by studies, neither does the ‘even an inch’ give an indication of the exact measure. In direct contrast, photographs of these glaciers in the report clearly show significant retreat – but it might be that photographs are not sufficient evidence.

The report also suggests that while glaciers are climate indicators, they need not respond to ‘immediate climatic changes’ for if that were the case, all glaciers in the region would retreat ‘equally’. Nevertheless, elsewhere in the report, an uneven retreat pattern across nearby glaciers has been justified on the grounds of local variations.

The report omits references to key scientific literature including GSI survey and studies including Vohra (1981) on Satluj River Basin glaciers, Shukla and Siddiqui (1999) on Milam glacier, all indicating significant retreat, and other scientific including the WWF (2005) report and the ICIMOD (2007) satellite-based studies and reviews on Himalayan glaciers across India, Nepal and China. It ignores known fact that small glaciers in the Bhutan (not so far away, as one may well see), have disappeared completely.

Glacier changes are recognized as high-confident climate indicators, and even considered as evidence for climate change by the IPCC. Reports from the World Glacier Monitoring Service (WGMS) indicate that measurements taken over the last century ‘clearly reveal a general shrinkage of mountain glaciers on a global scale’ (WGMS report). Despite this, this report suggests that ‘to postulate that a glacier can warn of climate changes likely to take place in the future is a big question mark’. In that case, even the IPCC might be wrong in assuming that rapid glacier retreat (even in the Himalayas) is a confident indicator of climate change!

The report awaits ‘many centuries’ of data to conclude that glacier snout movements are a result of ‘periodic climate variation’ or to make a statement that glaciers in the Himalayas are ‘retreating abnormally because of global warming’.

1 comment:

  1. Best estimates are that at current rates the glaciers disappear in 30-50 years. Anyone awaiting many centuries of data before they act is delusional