Shrinking glaciers, frozen earth melting, grasslands turning
yellow, rivers drying up, scientists studying the effects of global
warming on Tibet are deeply worried.
A group of scientists, organized by World Wildlife Fund (WWF),
have just explored the source of the Yangtze River on the
Qinghai-Tibet Plateau and reported alarming findings.
And on Monday 2 July the Tibet weather authority recorded the
highest July temperature in 30 years in Lhasa, the regional
capital.
"The glaciers at the source of the Yangtze River are shrinking
much faster than we had anticipated," said Li Yajie, a scientist
with the Nanjing Institute of Geography and Limnology under the
Chinese Academy of Sciences, who visited the area in the 1980s and
again in the 1990s.
The breathtaking view of Mount Yuzhu and 14 other snowy peaks
stuns passengers traveling along the Qinghai-Tibet railway.
But those who enter a typical glacier valley west of Mount Yuzhu
will no longer find any trace of a glacier at the snow line
altitude of about 5,000 meters.
In its place, a sliver of spring water bubbles its way down the
flank of the mountain.
Scientists found the remnants of the glacier on the far side of
the mountain.
"There are four stages in the disappearance of a glacier. Sadly,
this glacier is already in the last stage," Li said.
The Qinghai-Tibet Plateau used to boast 36,000 glaciers with an
area of 50,000 sq km which feed several of the major rivers in
China and Southeast Asia. In the past 100 years, the area of these
glaciers has shrunk by 30 percent.
Scientists say that if the temperature at the end of this
century is 2.1 to 4 degrees Celsius higher than now -- a reasonable
hypothesis given global warming trends -- this figure will increase
to almost half.
One of the most bitter paradoxes of global warming is the fact
that global warming does not have a positive effect on water
supply. As the glaciers melt, they provide water but most of this
extra water is vaporized in the warmer weather, Li said.
Data from the weather station along the Tuotuo River, the source
of the Yangtze River, testifies to this.
The whole of the Tanggula Range of mountains is suffering higher
temperatures, lower rainfall and greater vaporization losses, an
overall trend towards drier weather, said Lei Aiguo, deputy
director of the weather station.
Travelers on the Qinghai-Tibet highway have for years been
troubled by the bumpy and sometimes chaotic surface of the
road.
The concrete surface of the highway at Wudaoliang, a small town
at an altitude of 4,700 meters, is in very poor condition -- it
looks as though some giants had smashed it angrily with enormous
hammers.
The melting of the frozen earth beneath the surface is the cause
of 80 percent of the damage to the road on the Plateau. As the icy
core of the earth melts, the road subsides.
The warmer weather gradually releases carbon and hydrogen into
the air from the frozen earth, affecting the regional and even the
global climate, said Li Yajie.
The melting of the frozen earth has also impacted vegetation at
high altitudes.
Over the past 40 years, water losses due to global warming and
vaporization have reduced water volume in the earth in this region
and the grassland is drying out, said Li Yuanshou, scientist from
the Cold and Arid Regions Environmental and Engineering Research
Institute of the Chinese Academy of Sciences, who has been
monitoring the condition of the highland grasslands for three
years.
According to Li and his colleagues, 15 percent of rich grassland
and one fourth of wetland at high altitude have vanished in the
past 15 years.
Lots of countries around the world, including China, have begun
to make efforts to slow down global warming, Li Yajie said. "But
the scale of the problem is such that every nation and every
individual must get involved."
The scientists called for more support for ecological research
on the Qinghai-Tibet Plateau. They said that a foundation to
attract public donations and help fund the research should be set
up.
"Whether it's the air, the land, the water or the fauna and
flora, we still don't know enough about Tibet," Li said. "But we
have to act now to protect that unique and vulnerable
environment."
(Xinhua News Agency July 8, 2007)
