The Jima Yangzong glacier, the primary source of the mighty Brahmaputra river or Tsangpo for Tibetans is retreating in Tibet, China at an alarming pace. If nothing is done about it, the giant Indian river may run dry in another 50 years, a section of international experts have warned. A Chinese source have said that the Jima Yangzong glacier in not in a position like existed earlier.
Revealing the cause of the retreat or shrinking of the glacier experts have said that global warming is behind the phenomenon. According to UN climate change experts, the melting of Himalayan glaciers threatens 1.3 billion Asians living downstream. It could bring drought and diseases to large swaths of the continent. It is matter of grave concern that almost 1,000 sq km area of Himalayan glaciers has disappeared from total area of about 5,000 sq km. Like the Jima Yangzong glacier, two other glaciers which feed water to the Yarlung Zangbo are also melting and retreating rapidly, the Chinese source said. It is to be noted that the Himalayan region is warming about three times the global average with temperature increase of an average of 0.3 degree Celsius measured for the past half century.
According to Dr. Yang Yong the Jima Yangzong glacier area at 5500 meters has decreased substantially within last few years, The Chinese scientist if global warming continues at the current rate, the glacier as well as other glacier located at the same height will disappear within few decades. Under such circumstance, the scientist said the Yarlung Zangbo could become a seasonal river severely affecting the water flow or it could see a lean water flow in winter. The Chinese scientist had warned it few years back and now the people have witnessed it in Arunachal Pradesh and Assam, India. Dr Yong is a scientist in Hengduan Mountain Research Institute and Deputy Director of Expert Committee of China Foundation for desertification Control and he climbed the Jima Yangzong few years back.
Experts have said that glacier melting and glacial lake outburst cause Glacial Lake Outburst Floods (GLOF) and such floods carry morain to the lower part of the river and river bed becomes swallow. Stone mud and sand cover a vast area along the river. The areas covered by morain and sand along the river in Tibet are expanding every year. The growing desertification has become a big threat to the ecosystem in Tibet. It is assumed that morain carried by water may create problems in dams in Tibet. Dr Yong Zangbo in Tibet. Sands carried by the Yarlung Zangbo has turned many downstream stretches into sandy pitches. The river has become shallow and narrower at certain stretches.
Rapid melting of the glaciers in the Himalayan region will fast increase the volumes of water in rivers, causing widespread flooding. then in a few decades, the situation will change and the water level in rivers will decline, causing massive environment problems for people in western China, Nepal and Northern India. These phenomenons are already seen in the Brahmaputra river vividly. The changing landscape of the Brahmaputra river is clearly evident in Guwahati, the capital city of Assam in India. The river banks on both sides are inundated with large deposits of sand and it a indication of desertification spreading throughout the region. Once famous for its abundant run off even in winter the flow of the river is now reduced to a swallow level particularly in winter.
Many institution and scientists have conducted research on Himalayan glaciers for decades, warns of an urgent need for more research on the impact of climate change. With changing temperature, current trends in glacial melt suggest flows in mjor Asian rivers will be substantially reduced in the coming years. The Brahmaputra and other Himalayan rivers flowing through Northeast India will stop flowing within another five decades if nothing is done about the soaring global temperature.
(The writer is a Guwahati based science journalist, conservation activist, and Director, Wildflowers)