Zima Yangzong glacier the prime source of the Brahmaputra (or Tsangpo) is retreating like some other Himalayan glaciers attributed to the global warming. Chinese expert on Himalayan Mountain and Tsangpo Dr. Yang Yong said during an interview in Kathmandu (Nepal) last week. He said that if global warming continues at current rate the glacier as well as other glaciers in that same height will disappear within few decades and the river which is called Yarlung Zangbo in China will be a seasonal river. There would be no water or might be a lean water flow during the winter. According to UN climate-change experts, the melting of Himalayan glaciers threatens 1.3 billion Asians. Over a billion people in Asia depend on Himalayan glaciers for water, but experts say they are rapidly melting, thereby threatening to bring drought and disease to large swathes of the continent. It is matter of grave concern that almost 1000 sq km area of Himalayan glaciers have disappeared from total area of about 5000 sq km.
Dr. Yong, a scientist from Hengduan Mountain Research Institute and Deputy Director of Expert Committee of China Foundation for Desertification Control revealed that the original area of Jima Yangzong has been decreased substantially within last few years . The upper glaciers of the Himalayas are still stronger unlike the lower glaciers which are creating glacial lakes and Chinese experts finds in an spot survey that the Zima Yangzong is no exception at almost 5500 meter altitude. It is feared that if the glacier melt continues the glaciers will decrease in near future and it is almost sure when Jima Yangzong will be finished there will no substantial amount of water in Tsangpo. According to Dr. Yong there are two other glaciers linked with the Tsangpo as source of water and they are also melting and retreating fast like Jima Yangzong. It is to be noted that the Himalayan region is warming about three times the global average with temperature increase of average 0.3 degree C measured for the past half century.
Glacier melting and glacial lakes appears as a great threat to the source areas of the Tsangpo in Tibet in China. When lake water swells Glacial Lake Outburst Flood (GLOF) carries moraines to the lower part of the river and the river bed becomes shallow. Stone, mud and sand covers a vast area along the river. Moreover the areas covered by moraine and sand along the river in Tibet expanding every year. This growing desertification becomes a great threat to the ecosystem in Tibet. It is assumed that moraine carried by water may create problems in dam in Tibet., Dr Yong added. Replying to a question he revealed that desertification already started in the source of many rivers including Tsangpo the sand carried by the Tsangpo has turned many areas sandy along its downstream stretch. The river has also become shallow and narrower at some stretch due to climate change.
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 this situation will change and the water level in rivers will decline, meaning massive eco and environment problems for people in western China, Nepal and Northern India. These symptoms are already seen in the river (Brahmaputra) vividly. Experts say the effects of global warming are already being felt in the region.
The Nepal-based International Centre for Integrated Mountain Development (ICIMOD), which has conducted research on Himalayan glaciers for 30 years, warns of an urgent need for more research on the impact of climate change. Most experts accept that temperatures are changing, and this is happening more rapidly at altitudes. Current trends in glacial melt suggest flows in major Asian rivers will be substantially reduced in coming decades.