The UN agency in its website said India may see catastrophic results because of the shrinking glaciers as both the rivers are fed by large mass of snow on the Himalayas. This has been viewed with great concern in Assam, which has been punished by the flood waters for past half-a-century. ''Especially the Dhemaji district has been the worst hit by the floods and we are looking into this report with great concern,'' said a Brahamputra Board official.
The shrinking of glaciers was such a rapid rate that many could disappear within decades, the UN Environment Programme said on Sunday. The scientists said the warming would have a huge effect on India where the Himalayas feed its rivers.
Each year, beginning May to September, the mighty Brahamputra inundates the entire Brahamputra valley leaving a trail of devastation. With the river bed completely silted up specially in the upstream, it is actually a desert in the Dhemaji district which has been buried by the meandering rivers as they change course almost every week because of siltation as well as denudation, said Mr Ravindranath of the River Volunteer Force.
The UN report said the scientists measuring the health of almost 30 glaciers around the world found that ice loss reached record levels in 2006.
Nobel laurate R K Pachauri, Chairman of the Intergovernmental Panel on Climate Change (IPCC), last fortnight while visiting here warned the region of catastrophe if the natural resources were not protected.
''Neglect in protecting our heritage of natural resources could prove extremely harmful for the human race and for all species that share common space on planet earth. Indeed, there are many lessons in human history which provide adequate warning about the chaos and destruction that could take place if we remain guilty of myopic indifference to the progressive erosion and decline of nature's resources'', he said.
The UNEP warned that further ice loss could have dramatic consequences particularly, in India, whose rivers are originated from the Himalayan glaciers.
The west coast of North America, which gets much of its water from glaciers in mountain ranges such as the Rockies and Sierra Nevada, would also be affected, it said.
''There are many canaries emerging in the climate change coal mine,'' UNEP's executive director Achim Steiner said in a statement.
''The glaciers are perhaps among those making the most noise and it is absolutely essential that everyone sits up and takes notice.'' He urged the governments to agree stricter targets for emissions reductions at an international meeting next year in the Danish capital, Copenhagen. On average, the glaciers shrank by 4.9 feet in 2006, the most recent year for which data are available.
The Brahamputra valley has already felt the pinch and was getting ready for another year of devastation starting in next two months.
''There is no point fighting nature. At best we can take some precaution but over the decades it has been proved time and again that nature is supreme and the Brahamputra is too strong'' said Assam Water Resource Minister Bharat Chandra Narah.