Home  |  Contact  |  Sitemap  |  中文  | CAS 
About Us │ Research │ Scientists │ International Cooperation │ News │ Education & Training │ Job opportunities │ Papers │ Resources │ Links
  News
  Latest news
  Int’l Cooperation activities
  Events & Announcement
  Recent Activities
  Location: Home>News>Latest news
newsweek international reports of glacial retreat in Asia


Glaical retreat in Asia, especially on the Tibetan Plateau, has aroused interest and concern of a journalist fron Newsweek Internatioanl, Craig Simons, who reports of his interviews with glaciologists about the potential environmental problems caused by falling ice. The following is the full article for your reference. 

Beware of Falling Ice; Asia's glaciers are melting at an alarming rate,
creating a host of environmental problems from flooding to disease.

By Craig Simons
1,392 words
6 June 2005
Newsweek International
Atlantic Edition
 The Chinese ask river gods for protection against floods. Each year tens of
millions of Indian Hindus make pilgrimages to the Ganges to seek spiritual cleansing. In impoverished villages from Nepal to Bangladesh, waterways are the lifeblood of society, relied on for everything from drinking water to
industry to burial. The veneration that Asians hold for rivers was on Chu
Duo's mind as he fiddled with his instruments--a bevy of thermometers,
barometers, solar-radiation meters, rainfall gauges--in a small, flat field
near Lhasa's Jokhang Temple, Tibet's holiest Buddhist monastery. For the
past five years, Chu, a 36-year-old meteorologist at the Tibet Institute of
Plateau Atmospheric and Environmental Sciences in Lhasa, has been trying to
measure changes in the local climate. He found that temperatures have risen
more than 1 degree Celsius since the 1960s, while rainfall has increased.

The results aren't out of line with what climate scientists have been
finding for other parts of the world. But for the three fifths of the
world's people who live in Asia, the prognosis is especially dire.

The 2.5 million-square-kilometer Tibetan Plateau, which stretches from
Kazakhstan in the northwest to India in the south, is the main source of
Asia's big rivers--the Yangtze, Yellow, Mekong, Indus and Ganges. For
hundreds of thousands of years, more than 46,000 glaciers on the plateau
have provided a steady flow of water to the lowlands. Each winter the
glaciers have grown as snow has piled onto them. In May and June they begin
to retreat as some of the ice and snow melt. Until recently, they've stayed
pretty much the same size. But during the last several decades,
glaciologists have recorded more melting in the summer than gets replaced in
the winter. According to Yao Tandong, the director of China's Institute of
Tibetan Plateau Research, glaciers on the plateau have retreated an average
7 percent during the past 40 years, and the rate at which they are melting
is increasing. For glaciologists, the change has been abrupt: "By nature,
glaciers are slow movers," says Yao. "The glacial retreat has happened very
suddenly."

Because the glaciers are melting faster than usual, more water is pouring
out of the mountains and into the rivers. According to Yao, annual glacial
runoff on the Tibetan Plateau and surrounding areas is now equal to the
total yearly discharge of the Yellow River, roughly 20 percent more than 40
years ago. Some of that water is making its way into Asia's rivers,
increasing floods and spreading waterborne diseases. More of it is pouring
into valleys, enlarging old lakes and creating new ones. This glacial
melting is expected to continue at least at the present rate for many
decades. In the process, it will transform Asia, creating a host of new
environmental problems.

The increased melting has already begun to change the region's geography.
One lake in northern Tibet, Fuqilin Lake, has risen 20 centimeters a year
since 1997, spreading over local pastures and towns, and forcing residents
to move to higher ground. Occasionally the lakes break their embankments,
emptying tons of water into rivers and even dry valleys and causing
devastating flash floods. In Nepal, a series of landslides and flash floods
killed more than 350 people and left some 10,000 families homeless in 2003.

The struggle to contain rapid increases in water flow will occupy Asia for
decades to come. Glacial runoff has already contributed to massive floods in
India, China and Bangladesh. Flooding along the Yangtze River in 2002 caused
billions of dollars of damage and killed at least 1,000. Last year, floods
in India killed more than 1,000 and left millions homeless, while Bangladesh
suffered its worst floods in 15 years, with high water spreading deadly
diseases including diarrhea and cholera. Because glacial runoff peaks during
monsoon season in India and Southeast Asia, "it is very complex to separate
the two," says Joseph Gergan, a glaciologist at the Wadia Institute of
Himalayan Geology in northern India. But some experts say that glaciers, as
opposed to rainfall, are responsible for as much as 70 percent of the flow
of some of Asia's largest rivers during the late summer, up from some 60
percent in the 1960s.

Another problem is that as glaciers and permafrost melt, rivers wash away
more loose topsoil. In China the problem of river silting is particularly
acute. China has the largest number of large dams in the world--148 on the
Yangtze River basin alone--and as mud and debris backs up behind them, the
dams require expensive dredging that doesn't always work. Opponents of the
Yangtze's Three Gorges Dam, the world's largest, point to a recent U.S.
study that found silt buildup in U.S. dams amounts to 2 cubic kilometers
each year. Because the Yangtze carries the fifth-largest sediment discharge
of any river in the world, silt trapped behind the dam could render the
river impassable for large ships.

In the longer term, the problem will reverse. Yao predicts that 60 percent
of the glaciers on the Tibetan Plateau will be gone by the end of the
century and that the average volume of most Asian rivers will begin to fall
in 2050. The flow of several Ganges tributaries fed by shrinking glaciers in
southeastern Tibet has already declined by 40 percent, says Shen Yongping,
the author of a recent WWF report on glacial melting. The problem will be
more acute in inland rivers, which do not feed into larger rivers or reach
the sea but eventually dry up as water is siphoned out. In China's
northwestern Xinjiang province, Shen says, 60 percent of the Kumarik River
originates in glacial runoff, and many other rivers in the province are also
primarily glacial. "People are moving to parts of Xinjiang where there is
increased flow that they can use for agriculture and industry," he says.
"But in 10 or 20 years the flow will begin to abate. Once the rivers
decrease and finally disappear, the oases will dry up and there will be no
more cities."

Reduced flows will also have a severe impact on China's heavily populated
northeast. China's per capita water resources are about one quarter of the
world average, and in northern China that ratio drops to one twentieth. Most
of the rivers in eastern and northern China are so polluted that making them
fit for drinking is prohibitively expensive. Water tables around major urban
areas, including Beijing, are dropping, forcing the cities to transport
water from elsewhere.

So far Asian governments have been slow to react. In Nepal and the tiny
Buddhist nation of Bhutan, a recent United Nations Environmental Program
project located 44 new or growing glacial lakes threatening nearby villages.
In China scientists are using satellites to track rising lake volumes and
will evacuate villagers if a glacial flash flood seems imminent. Beijing has
invested $24 billion to build a reservoir in Xinjiang province to prevent
flooding and to control rampant water use. But with glaciers melting over an
area as large as one fourth of the United States, Yao says, those efforts
will yield limited benefits and, regardless, won't slow climate change.
"Officials," he says, "don't really take a long-term view."

Environmental groups appear ready to push the issue. The U.N.'s annual
environmental report, issued in February, highlighted glacial melting, and
the Intergovernmental Panel on Climate Change--a group established by the
World Meteorological Organization and the United Nations--has made glacial
retreat a top issue. Former U.S. vice president Al Gore is expected to visit
a glacial monitoring station near Lhasa this summer to raise awareness. Yao
believes that while there "is probably no way to stop the glacial melting,
there are ways to slow it down." That would require a global effort to
reduce carbon emissions dramatically, which isn't likely to happen anytime
soon. For Asia, Yao thinks, it's probably better to prepare for the
consequences.

 

 

 
Copyright ©2003- Institute of Tibetan Plateau Research, Chinese Academy of Sciences
Email: itpcas@itpcas.ac.cn