The health of glaciers as an index of climate change, water storage and regulation has been a matter of concern in discussions on the changing hydrology of the Indus. An Indus Basin study group was benefited by a visit to Quito, Ecuador, to learn from the experience of the Andean glacier monitoring study, being conducted over the past 20 years.
Over 40% of the Indus run-off comes from glacial and snow melt. The cloudburst and glacial lake overflow that caused the Kedarnath disaster last summer are indicative of climate-related hazards.
As the Andean glaciers had been exhibiting signs of shrinkage, Colombia, Bolivia, Ecuador and Peru decided to measure the changes and plan appropriate mitigation measures. They set up a Great Ice Network. Fifty glaciers have been monitored. Of those six have been ‘benchmark glaciers’ that are more intensively studied. Temperature, humidity, precipitation, runoff, wind velocity, accumulation, ablation, mass balance and vertical temperature gradients, measured through deep core drill and other parameters, are recorded to establish trends, seasonality, aspect factors and other data.
Glacial retreat has affected hydrology, hydro-power, biodiversity, avalanche patterns, and glacial lake formation, with risks of floods and drought.
The tropical Andean experience may not apply in the Himalayan-Karakoram-Hindu Kush (HKHK) scenario. Yet the sharing of climate change data and adaptation and mitigation techniques is useful. At the Quito meeting, data sharing showed mixed trends on glacier behaviour. Afghanistan (Hindu Kush) has 27 watersheds, 25 glacial sources and 3,000 glaciers with a spread of 2,700 sq km (1970). Afghanistan would greatly benefit from data sharing, satellite imagery support and assistance in reconstructing its war-shattered hydro-met and water and sediment discharge monitoring network.
Pakistan’s meteorological department is expanding its cryosphere-monitoring network, covering 7,159 glaciers spread over 11,780 sq km, mostly in the Karakoram. A telemetric system is being developed and there is evidence of glacial melt. However, scientists are also puzzled over the ‘Karakoram Anomaly’, which suggests that the Karakoram glaciers are by and large in a stable state as compared with glacier retreat elsewhere in the world. Simulation studies are being conducted in the 12,000 sq km Central Karakoram National Park to forecast glacial retreat and its impact as temperatures rise.
The Chinese are expanding their hydro-met network of 2,500 stations and are conducting simulation studies up to 2,050 on the basis of five models. Their finding is that Himalayan glacier retreat is the highest in the world. Indian glacier studies over the past century show Himalayan glaciers in retreat. There has only been a limited recession in the Siachen Glacier since 1995, alarmist estimates notwithstanding.
Hydro-met data along the HKHK axis merits considerable augmentation with climate change impacts manifesting themselves. Monitoring the consequences of Tibetan permafrost melt and Karakoram glacier behaviour is of particular importance and calls for close cooperation with China and Pakistan. The creation of a NJ9842-K2-Karakoram Pass Global Scientific Reserve has been canvassed and this could be augmented with advantage were China to join by adding Shaksgam to the international reserve. Glacial lake formation in the remote heights, cloudbursts and aberrant weather conditions and hydrological and sediment-load variations are posing fresh dangers that need to be closely monitored. Adaptation and disaster preparedness and management protocols must be evolved to ensure that damage is avoided or at least minimised.
Climate change respects no frontiers or treaties. We must cooperate regionally and globally to manage our common future.
BG Verghese is a well-known columnist
The views expressed by the author are personal