Hard science

Pradeep Kumar Mool is a specialist in remote sensing at the International Centre for Integrated Mountain Development (ICIMOD) in Kathmandu. In his current capacity, he studies snow and glacial monitoring, glacial lakes and the risk of Glacial Lake Outburst Floods (GLOFs). Mool spoke to Himal Southasian on the status of ice and water in the region and the Centre's new research conclusions.

What specific observations of precipitation patterns in the region have been made – how much falls in the form of snow, how much in the form of rain?
Very little data on precipitation patterns is available for the region. Few instrumental meteorological observation stations or automatic weather stations exist in high-altitude areas, especially those that include rain and snow gauging. The World Meteorological Organisation, the global agency of the United Nations, specialises in data collection of meteorological, hydrological and other geo-physical observations. It shares meteorological and related data collected by stations worldwide in near real time, through a Global Telecommunication System (GTS). Unfortunately, there are no GTS gauging stations above the snowline for the Himalayan region.

While older data may exist, it is often not available due to national-security concerns. Collection of shareable snow-gauging information along the southern slopes of the Himalaya began only in the last 10 to 15 years. Along the northern slopes, snow gauging started one to two decades back in various glaciated basins in Tibet, including at the Rongbuk Base Camp. The Chinese have recently installed automatic weather stations in the high mountain areas at elevation intervals of 100 metres, from the toe to the tip of the mountain. These stations gather data at every altitudinal zone recording precipitation changes, temperature changes and snowmelt rate. Despite scattered data-gathering, the results generated from these minimal initiatives are not sufficient to make definite conclusions on precipitation in the Himalaya. Snow gauging would be particularly important for the western Hindukush-Himalaya, where the predominant winter monsoon falls in the form of snow. Most of the input to the Indus River basin therefore comes from snowmelt, which includes glacial melt, compared to the primarily rain-fed rivers originating in the Eastern Himalaya such as the Ganga, Brahmaputra and the Meghna. If we look at the Indus basin, input of glacier melt is up to 50 percent; but when we look at the Ganga, reports vary from two to nine percent. If snowmelt would also be accounted for, the contribution to the Indus river basin could go up to 70 or 80 percent in the dry season.

While hard science may be lacking, lay observations can also give us a sense of the changing precipitation trends. Two years back, heavy winter monsoons in Afghanistan and Pakistan were followed by snow avalanches and intense flooding. This is a dramatic shift from reports of drought in the late 1990s – to the extent that, as rumours have it, authorities and scientists recommended spreading charcoal on glaciers to accelerate glacial melt, thereby reducing water-shortage tensions along the Indus basin.

In another example, Asaar Pandra, the day marking the beginning of planting paddy in Nepal, usually falls at the peak of the summer monsoon's arrival. For the past few years, however, the summer monsoon has been highly disturbed, and therefore does not tally with the annual cropping calendar. Overall, we see more cases of short-duration intensive rainfall today, and general shifts in the onset of the monsoon.

Where else, besides precipitation-gauging stations, do you see the need for more study? And what do the current studies lack in terms of depth of research?
It has already been established in the global and regional scenario that temperature is rising. Many national and basin-wide models and predictions are also available, verified by field observations. In Nepal, the average temperature increase for the last decade was 0.06 degrees Celsius per year. On the Tibetan Plateau, warming has been in the range of 0.016 to 0.032 degrees per year. Yet when it comes to high-altitude temperature analyses, there are no continuous records of observations for the Himalaya.

Aside from high-altitude temperature and snow-gauging stations, we also need to conduct more studies on how much of that snow converts to ice, because ice stored in glaciers is considered a long-term water reserve for the region. The quantity of snow that converts to ice is an important parameter for eventually determining glacial mass balance – another factor in need of significant study. There are scattered and discontinued studies of glacial mass balance in the region. China conducted a long term glacial mass balance observation on Tian Shan Glacier Number 1.  India, Nepal and Pakistan have only recently begun glacial-mass-balance monitoring through field investigation. About two years back, various institutions coordinated by the Government of India started glacial-mass-balance studies of ten glaciers in India, from Kashmir to north-eastern India. In Nepal a glacial mass balance study has begun on the Mera glacier. To support these endeavours, ICIMOD conducted a regional training earlier this year on the Yala glacier, in the Langtang region of Nepal, to disseminate practical skills on how to measure and calculate the mass balance of a glacier.

The fourth IPCC [the UN's Intergovernmental Panel on Climate Change] Assessment Report contained no supportive data from the Hindukush-Himalaya region. The identification of this crucial gap escalated plans to initiate scientific study and provide input to future reports. It will take a few more years to assemble conclusive data, but indications have already emerged over the past two years. For example, in the Karakoram, some fieldwork report glacial advances. We do not know, however, whether this is simply an expansion of the surface, or whether it also corresponds with an increase in volume. For this, we would need data on the actual mass balance of the Karakoram glaciers. A few glaciers in China have also been found to advance, and reports by the Chinese Academy of Sciences determined a positive mass balance. Nevertheless, most glaciers on the Tibetan Plateau have been identified as having a negative mass balance. Glaciers are depleting; but whether the glacial mass is decreasing in the same fashion that the international community suggests it to be, we cannot say for certain. The rivers of ice may be vanishing, but we cannot confirm at what rate this is happening.

Now, a coordinated mapping effort for the entire Hindukush-Himalaya region has only recently been attempted by ICIMOD, in association with the responsible national institutions. By 2010, some comprehensive statistical base should be generated for the glaciated area of all basins in the region.

Besides the glaciated surface area, ICIMOD has also begun to map the total snow cover for the entire Hindukush-Himalaya (HKH) region. Do you have some preliminary findings?
Just this month, we calculated the snow cover for the HKH region, derived from MODIS data, a satellite senor system, of eight-day snow cover. The total area of the HKH region is 419,624,400 square kilometres. Of this, the maximum snow-covered area in mid-February 2007 was 1,570,182 square kilometres, amounting to 37 percent of the region; and 214,780 square kilometres, five percent of the total area, in mid-July 2007. Snow cover differs from glaciated area in that snow is loose and not compact. Snow melts within a season or within a few years, while ice can retain as such for decades. When we measure glacier cover, we are actually measuring compact, perennial ice. When fresh snow compresses and metamorphoses into glacial ice, it then contributes to the glacial mass balance.

One report states that Himalayan glaciers will shrink from the present 500,000 sq km to 100,000 sq km by 2035; while another study claims that the Himalayan glaciers, in total, cover just over 100,000 sq km. What can you say about this discrepancy?
There is a lot of misinformation taking place. Climate change is a hot topic, and many feel the need to say or write something even just based on assumption. It is very difficult for me to understand where the above-mentioned data set would come from, since no accepted base data for the total glaciated area in the region exists. Even the Chinese government only recently published a paper reporting five percent reduction in glacial cover in the past two decades. Based on that five percent, postulating a five times decrease of ice would be difficult to accept. One 2009 estimate by ICIMOD shows the present glaciated area in the greater Himalayan region and its surroundings to be about 112,000 sq km, however even these results are sourced from limited available data.

In fact, factual data is missing, and most of the scientific community is not coming forward to publish the facts in a clear and concise manner. The existing inventories, often unpublished due to national-security concerns, are generally based on very old data sets, with little current validity. This is in addition to the lack of uniformity in methodology across country studies.  Even looking at the movie An Inconvenient Truth, in which Al Gore claims that glacier AX010 in the Shorong Himal of Nepal will be gone in a certain number of years, one questions the basis of such a suggestion. Mass-balance studies have been conducted for the region, but only very recently. Without long-term analysis, it would be difficult to make definite predictions.

Often the onus is on the scientists themselves, who fail to talk about their findings in a language that the media and the public can understand. This leads not only to misinformation but to an irrational sensationalising of the issue at hand. I remember back in 1997, when a lot of distorted information was publicised about the Tsho Rolpa glacial lake in the Rolwaling valley, Dolakha District of Nepal. Some media reports claimed that if the glacial lake was to burst its banks, there would be drastic flooding in the Kathmandu Valley. In reality, this would be impossible, since Tsho Rolpa is in a completely different catchment from the Kathmandu Valley. Correct information is very important for the general public, from local farmers and villagers, to local politicians, planners and the media.