Dharamsala, March 4
Glaciers in the upstream
basin of the Brahmaputra, a 2,900-km-long river that originates from
Tibet and flows into the Bay of Bengal, are likely to reduce alarmingly
by the middle of the 21st century, according to an international body
which also warned that the overall flow in the river was likely to
increase.
"Hydrological modelling was carried out in the upstream
areas of the Brahmaputra, which indicate the glaciers are likely to
reduce by 20 to 55 percent by 2050," Nand Kishor Agrawal, programme
coordinator for the Kathmandu-based International Centre for Integrated
Mountain Development (ICIMOD), told IANS.
He said there were chances of increase in total water flow in the Brahmaputra.
"By
2050, the total runoff is likely to increase from zero to 13 percent
due to fast melting of glaciers and increased precipitation," said
Agrawal, who travelled to Tibet to study impacts of climate change on
the ecosystem and the communities.
About 60 percent of the inflow in the Brahmaputra is from rains. The remaining is from the glaciers, base flow and snow melt.
The
feedback gathered by the ICIMOD from the pastoral communities settled
in Tibetan plateau has indicated that the climate has changed a lot,
resulting in uneven flow in the river.
"They say sometime the
flow increases suddenly and sometime decreases drastically, which simply
indicates the governments have to be prepared for the unexpected floods
and draughts," said Agrawal, who was in India for the workshop on
climate change adaptation in the western Himalayas.
Studies
conducted by the Tibetan administration in exile, which is based in this
northern Indian hill town, say the Tibetan plateau is staring at
ecological destruction.
"Human activities are mainly responsible
for the destruction of Tibet's ecological balance," said in its report
titled "A synthesis of recent science and Tibetan research on climate
change".
It said the temperature increase on the Tibetan plateau
was twice the global average, resulting in quicker degradation of
permafrost, drastic change on climate pattern and desertification of
vast grassland.
To protect the Tibetan plateau from certain
destruction, the report said there was a need for a water sharing treaty
among the countries of the region and of making the Tibetan plateau an
exploitation-free international observatory zone.
Climate
researchers at the University of East Anglia and the Chinese Academy of
Sciences in an online paper in US academic journal Proceedings of the
National Academy of Sciences say the wettest individual year
reconstructed in 3,500 years in northeastern Tibet is 2010.
They
say precipitation during the past 50 years in the plateau has been
historically high. They have reconstructed precipitation records by
using sub-fossil, archaeological and living juniper tree samples from
the plateau.
Tibetan spiritual leader and Nobel laureate the
Dalai Lama has been saying his homeland Tibet is currently vulnerable to
climate change.
"Many of the rivers which flow through large
areas of Asia, through Pakistan, India, China, Vietnam, Laos and
Cambodia, rivers such as the Yellow river, Brahmaputra, Yangtse, Salween
and Mekong, all originate in Tibet.
"It's at the places of
origin of these rivers that large-scale deforestation and mining are
taking place. The pollution of these rivers has a drastic effect on the
downstream countries," a post on his official website quoting the Dalai
Lama said.
ICIMOD researcher Agrawal warned: "The current data
indicates more flood risks in the future. If the Brahmaputra is not
managed in Tibet, it will affect India and Bangladesh more."
Currently,
he said, the flooding in the river is not directly affecting the
grasslands in Tibet, but may be this will never happen in the future.
"But its flooding can affect more in the downstream areas mainly in the floodplains of Assam," he added.
The
ICIMOD has been carrying out studies in Tibet and India's Arunachal
Pradesh and Assam districts under the Himalayan Climate Change
Adaptation Programme in collaboration with scientists from China and
India.
(Vishal Gulati can be contacted at vishal.g@ians.in)
