Western disturbances give Karakoram glaciers climate change resilience
By Our Special Correspondent
New Delhi, July 18: Himalayan glaciers are bearing the brunt of the climate change, yet the Karakoram Range holds on to its mass, fueling several theories among the scientists.
The scientists, while decoding the intrinsic strength of the Karakoram Range to withstand the impact of climate change, has zeroed in on to a phenomenon called ‘Karakoram Anomaly’ to explain the exceptional behavior, which is attributed to the recent revival of western disturbances (WDs).
It’s in contrast to another study on glaciers in the Drass sector in Ladakh which have lost five square kms in the last two decades. The highest glacier on Mount Everest is being project to fully melt by the end of the century.
Himalayan glaciers, incidentally, are of paramount importance in the Indian context, especially for the millions of dwellers living downstream who rely on these perennial rivers for their day-to-day water needs.
Such glaciers are fast receding under the impacts of global warming, and stifling stress on the water resources is inevitable in the coming decades.
In contrast, the glaciers of central Karakoram have surprisingly remained unchanged or slightly increased in the last few decades.
A recent study conducted under the supervision of Dr. Pankaj Kumar, Associate Professor at the Indian Institute of Science Education and Research (IISER) Bhopal, has postulated a new theory to explain this defiance of the impacts of global warming.
In a paper published in the American Meteorological Society’s Journal of Climate, his group claimed that the recent revival of western disturbance has been instrumental in triggering and sustaining the ‘Karakoram Anomaly’ since the advent of the 21st century.
The study was supported by the Climate Change Programme of the Department of Science and Technology.
“It is for the first time that a study brought forth the importance that enhanced western disturbance precipitation input during the accumulation period plays in modulating regional climatic anomaly,” said the Ministry of Science and Technology in an official statement.
Aaquib Javed, a researcher and lead author of the study, said, “The western disturbances are the primary feeder of snowfall for the region during winters. Our study suggests they constitute about around 65 percent of the total seasonal snowfall volume and about 53 percent of the total seasonal precipitation, easily making them the most important source of moisture. The precipitation intensity of WDs impacting Karakoram has increased by around 10 percent in last two decades, which only enhances their role in sustaining the regional anomaly.”
The group compiled a comprehensive catalog of WDs impinging the Karakoram-Himalayan region in the last four decades.
The analysis for the tracks passing through the Karakoram reveals the role of snowfall as a crucial factor in mass balance estimations.
Calculations by the scientists reveal that contribution of western disturbances in terms of snowfall volume over the core glacier regions of Karakoram have increased by about 27 percent in recent decades, while precipitation received from non-WD sources have significantly decreased by around 17 percent further strengthening their claims.
“The anomaly provides a very bleak but nonetheless a ray of hope towards delaying the inevitable. After recognizing the importance of WDs in controlling the anomaly, their future behavior might very well decide the fate of Himalayan glaciers as well,” Dr. Kumar pointed out.