Despite the IPCC’s statement that they were wrong to include references to the possibility that Himalayan glaciers could vanish by 2035 – an assertion that has no scientific credibility – the question is still being asked: Are the Himalayan glaciers shrinking because of global warming? The answer is not clear.
A recent comprehensive report by India’s Ministry of Environment and Forests compiled by glaciologist Vijay Kumar Raina concluded that there was no evidence that they were responding to global warming.
Himalayan ice and snowfields cover in excess of 30,000 square kilometers. Since the 19th century records show that most glaciers advanced through that century as the Little Ice Age declined. In general, glaciers began to recede in the early 20th century. Since 1960, almost a fifth of the Indian Himalayas’ ice coverage has disappeared.
Raina’s report, agrees with this general picture but disputes the connection with global warming adding that many Himalayan glaciers are now stable or have advanced, and that the rate of retreat for many others has declined.
For example, the report discusses the 30-kilometre-long Gangotri glacier, source of the Ganges River. It receded at an average of 22 metres a year between 1934 and 2003. But in 2004 it slowed to 12 metres a year, and since 2007 has stopped.
The Siachin glacier in disputed Kashmir has, according to data soon to be published, has grown in the past 40 years. The findings are based on measurements by Dr R K Ganjoo, director of the Institute of Himalayan Glaciology in Jammu University.
Dr Ganjoo found that while the east flank of the 80 km long glacier has lost 0.65 sq km area, the west flank has gained 2.41 sq km. Overall, the glacier has gained 1.76 sq km in the past four decades.
Dr Ganjoo’s study of the 23-km long Durung Durung glacier did not show it has retreated. “The climate analysis of the area did not point towards any major change affecting the glacier’s health,” he said.
Glacier monitoring is not easy or straightforward. Many glaciers lie above 3,500 – 4,000 metres in altitude, rendering them virtually inaccessible. “There are roughly 50 glaciers that have been worked scientifically,” says Dr. Ganjoo, “Frankly speaking, 50 glaciers are absolutely a tip of the iceberg to get an idea about the other 9,575 Himalayan glaciers.”
The Executive Summary of Raina’s report concludes: It is premature to make a statement that glaciers in the Himalayas are retreating abnormally because of the global warming. A glacier is affected by a range of physical features and a complex interplay of climatic factors. It is therefore unlikely that the snout movement of any glacier can be claimed to be a result of periodic climate variation until many centuries of observations become available. While glacier movements are primarily due to climate and snowfall, snout movements appear to be peculiar to each particular glacier.
Clearly, much more research is needed. It has been said that we know less about the Himalayan glaciers than anywhere else on the planet. India’s environment minister, Jairam Ramesh, says, “We don’t need to write the epitaph for the glaciers, but we need a concentrated scientific and policy focus on the Himalayan ecosystem since the truth is incredibly complex.”