Heat on the Mountain
The Indian Sunday Express, Sept. 15, 2002 As bugs invade areas deserted by the cold, the latest satellite studies confirm a retreat of the ice, probably from global warming. Could the Himalayan glaciers be gone in 30 years? asks Samar Halarnkar
Like aircraft carrying paratroopers, they ferried the invaders within themselves. The winged aphids swooped down on the willows of Lahaul-Spiti this summer, furiously depositing wingless nymphs. Within a week, each nymph produced 60 offspring, mostly females. The count in a few weeks: hundreds of thousands. Like last year, the tree that meets most of the fuel and fodder needs of the local tribals is being ravaged.
The mountains of Himachal Pradesh simply haven’t been cold enough to stop the northward forays of the aphids. Later this month, a team of scientists from Simla’s Himalayan forest Research Institute will head out to determine the extent of the aphid attacks.
Many climate zones and half a subcontinent away in Ahmedabad, Dr Anil Kulkarni knows nothing of the aphids. But the satellite images before the Indian Space Research Organisation (ISRO) scientist might explain why insects that hate the cold are beginning to infest snow-bound areas: there simply isn’t enough snow.
Every tourist operator and villager in the middle Himalayas will tell you how the winters haven’t seemed cold enough. The snowline has receded. Many of the glaciers they used to trek to as kids have retreated uphill. In the plains’ reservoirs consequently, there’s been more water.
Dr Kulkarni’s study of eight glaciers near the tourist town of Manali revealed melting snouts of glaciers, pushing vastly more water into mountain streams. ‘‘The stream run-off during the last 29 years has gone up by almost 75 per cent,’’ says Dr Kulkarni, Principal Glaciologist with the Space Applications Centre. He and his team used data from the Indian Remote Sensing Satellite 1-C to study the eight glaciers in the basin of the Baspa, a tributary of the Sutlej.
A similar ISRO satellite study is now underway in the Chenab basin, but the vast majority of 6,500 Himalayan glaciers is unsurveyed. The ongoing great melt has also prompted the government of India and UNESCO to organise a multinational training programme — both in Delhi and on the field at a Himachal glacier — in late September to update glaciologists on the intricacies of how glaciers are affected by global warming.
Disturbingly, Kulkarni found snowmelts at the previously ice-bound height of 5,400 metres during the peak winter months of December and January over the last four years. These observations match the steady rise in global temperatures and a steady warming at Manali, which was about five degrees warmer the past winter.
‘‘All these arguments and observations suggest that global warming has started to affect snow melt and stream run-off in the Himalayas,’’ says Dr Kulkarni, who studied stream run-off data in the Baspa basin since 1966. His study appears in the latest edition of the London-based Journal of Glaciology and the Indian Current Science Journal.
For now, the consequences aren’t bad actually. In this year of weird weather and a malfunctioning monsoon, Punjab’s key Bhakra-Nangal reservoir was filled by the melting glaciers feeding the Sutlej, even though there were no rains in the catchment areas. That’s something the experts watch with disquiet. ‘‘A lot of water coming in is not something to feel happy about,’’ notes Syed Iqbal Hasnain, head of the Glacier Research Group at Delhi’s Jawaharlal Nehru University. ‘‘A time may come when we will get no water at all.’’
Further east from the Baspa, Hasnain in July saw more evidence of the retreat of the Gangotri glacier, which feeds the mighty Ganga. The glacier’s snout — an ice wall that marks its furthest extent — was breaking up over a third of its 30-km stretch like never before. ‘‘There is no doubt the glaciers are melting,’’ says Hasnain.
Only last year, scientists at the Garhwal Hill University found the rate of retreat of the Gangotri glacier in the last 30 years was three times the rate in the last 200 years. Scientists have always worried that Himalayan glaciers are retreating faster than in any other part of the world. ‘‘If the present rate continues, the likelihood of them disappearing by the year 2035 is very high,’’ a 1999 report of the Working Group on Himalayan Glaciology of the International Commission for Snow and Ice had observed. ‘‘Himalayan glaciers are particularly sensitive to climate changes,’’ notes Hasnain. He points out that these glaciers are unique in that they get snow in the monsoon. A change of 0.5 deg C changes the ice to water.
So the Himalayas — home to the biggest concentration of glaciers after the polar regions — are turning out to be important proving grounds for further glacier studies. In December last year an international programme called the Global Land Ice Measurement from Space — dedicated to the world’s mountain glaciers — came online, with the South Asia centre based at JNU. As for the South West Asia Centre covering the high mountains of Pakistan and Afghanistan, well, it’s situated in Omaha, Nebraska. As Hasnain notes, ‘‘Who will be mad enough to go Pakistan’s borders to study glaciers?’’
Science has some way to go before we know the mechanics of the meltdown. Experts say it will take a couple of years to test the scientific models that could quantify the melts. It’s not easy to work on large, remote glaciers. And looking in from space can be misleading in a land of steep valleys and deep shadows.
What appeared to be lakes in an American satellite image turned out to be broken ice on physical verification many months later.
Scientists can thus only speculate on the cascading effects of melting glaciers and warmer weather. Some predict the advance of creatures like the aphids, previously held to lower altitudes by the cold and snow. Others forsee floods downstream as woollies are increasingly cast off in the mountains. Until science tell us what exactly is going on, we can only wait — and watch for the aphids.
Indian Express, Sunday September 15, 2002