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The Qinghai-Tibet plateau is home to tens of thousands of glaciers, fields of
ice at the roof of the world where Mount Everest and other Himalayan peaks look
down on China and Nepal.
But the glaciers are melting faster than anyone thought, fresh research by
Chinese scientists shows, as global warming speeds up the shrinkage of more than
80 per cent of the 46,377 glaciers on the lofty plateau.
Rising temperatures on the ice fields of Qinghai-Tibet and surrounding areas in
the past 50 years are having a devastating effect on the environment, as
receding glaciers translate into water shortages in China and huge swathes of
south Asia.
China will soon have to add more deserts, droughts and sandstorms to its already
lengthy list of pollution woes, while India and Nepal will have to deal with
staggering environmental consequences, as the melting lakes of ice threaten
essential natural resources for the large population centres at the foot of the
mountain ranges.
About 47 per cent of China's glaciers are on the Qinghai-Tibet plateau in the
Himalayas, where the Yangtze, Yellow, Brahmaputra, Mekong and Salween rivers all
originate.
The rate of melting, estimated at some 7 per cent a year, has meant more water
run-off from the plateau, which worsens soil erosion and leads to
desertification.
It is an environmental nightmare for rivers such as the Yangtze, 20 per cent of
which is fed by glaciers, while the Taklamakan Desert in north-west China could
be flooded before later drying out, researchers say.
Research just released by China's leading scientific body, the Chinese Academy
of Sciences, shows global warming is dealing a hammer blow to ice fields at some
of the world's truly awesome mountain regions.
This week the United Nations warned that Tibet's glaciers could disappear within
100 years due to global warming.
"Almost all glaciers in China have already shown substantial melting," the UN
Development Programme said in its 2006 Human Development Report. "This is a
major threat to China's over-used and polluted water supplies. The 300 million
farmers in China's arid western region are likely to see a decline in the volume
of water flowing from the glaciers."
The melting glaciers have not led to more water flowing into China's dry north
and west because much of the melted glacier water is evaporated before it
reaches the country's drought-stricken farmers, again as a result of global
warming.
In the past 40 years, glaciers across the Tibetan plateau that spills from China
into South Asia have shrunk by 6,600 square kilometres, especially since the
1980s, the conservation group WWF said in a 2005 report. The glaciers now cover
about 105,000 square kilometres, it said.
It is not just the glaciers of Tibet that are melting - 95 per cent of Alaska's
glaciers are thinning, too. Global temperatures rose about 0.6C during the 20th
century, and the consensus among scientists is that warming will continue as
long as greenhouse gases, primarily carbon dioxide from the burning of fossil
fuels, accumulate in the atmosphere.
China is the world's fastest-growing major economy, but it has only a quarter of
the world's average water per person, and rampant economic growth has sharpened
competition for water resources.
The Qinghai-Tibet plateau covers 2.5 million square kilometres - about a quarter
of China's land surface - at an average altitude of four kilometres above sea
level. The world's highest ice fields are a natural biological museum for the
array of geological phenomena they contain.
The temperature has risen by 0.2C every 10 years, according to the Cold and Dry
Zone Environment and Engineering Research Institute of the Chinese Academy of
Sciences. The institute's scientists selected 5,000 glaciers in the region for
study, using remote sensors and other methods for gathering geographical
information, to monitor changes over the past 50 years, Liu Shiyin, one of the
scientists taking part in the programme, told the Xinhua news agency.
The results were harrowing. Liu said only a small number of glaciers were
expanding and about 82 per cent of the monitored glaciers had receded by 4.5 per
cent in the past 50 years.
The rate of shrinkage in glaciers in the central and northwestern parts of the
Qinghai-Tibet plateau was slightly slower, but it was noticeably faster in
neighbouring areas.
Of 170 glaciers on the northwestern slope of the Qilian Mountains, a range of
peaks in the northern province of Gansu formerly known as the Richthofen Range,
95 per cent had thinned by 4.9 metres each year on average. Only 10 glaciers had
expanded during the period.
In the Tianshan Mountains in Xinjiang province, almost all the glaciers on the
northern slopes, and 69 per cent of glaciers on the southern slopes, were
dwindling.
In the Pamir Mountains of Central Asia, site of the 72km long Fedchenko Glacier,
the world's longest ice field outside the polar region, the glacier acreage
shrank by 10 per cent.
Glaciers on the northern slopes of the Kunlun Mountains, which stretch for
3,000km to form the border of Northern Tibet, are shrinking, as are the ice
fields of the Himalayas, which are home to the world's tallest mountain, Mount
Everest.
Global warming is causing China's highland glaciers, including those covering
Everest, to shrink by an amount equivalent to all the water in the Yellow River
every year.
Monitoring results show the flow of water in some rivers in north-west China's
dry regions has been increasing, which was possibly a result of melting
glaciers, Liu said.
Liu warned that if glaciers continued to melt at such a high rate, it "would
impose serious impact on local production and the life of local people".
In Nepal, where temperatures rise an average of 0.06C per year, snow-fed rivers
are declining, and water levels are getting lower on the wetlands of the Qinghai
Plateau.
Melting icefields are expected to trigger more droughts in an already parched
China, expand desertification and increase the frequency of sandstorms.
Han Yongxiang, a meteorologist, said average temperatures in Tibet have risen by
nearly one degree centigrade since the 1980s, accelerating the melting of the
glacier and frozen tundra of the Qinghai-Tibet plateau.
The desert is creeping right up to the edge of Beijing, despite the planting of
millions of trees to stop the sand's onset.
Drought is a fact of life and sandstorms are getting worse every year in north
China. A strong sandstorm swept across huge swathes of the country last month.
One particularly virulent storm dumped 330,000 tonnes of dust on Beijing and had
an impact as far away as South Korea and Japan.
It has been known for some time that the glaciers are melting. Last year,
scientists said three quarters of the glacier in the south-east of Tibet, and
the marine glacier along the Hengduan mountains, a series of parallel mountain
ranges running through the provinces of Sichuan, Yunnan and Tibet, would fade
away by 2100 if the temperature rises by 2.1C.
Earlier this year the Chinese ran a railway line across the plateau for the
first time. China has ruled the remote mountainous region of Tibet since 1950.
Water shortages due to overuse affect 538 million people in northern China,
where 42 per cent of the country's population is supplied by 14 per cent of the
country's water, according to the UN report this week.
The report said that more than 70 per cent of the water in the Yellow, Huai and
Hai rivers, which between them supply about half of China's population, is too
polluted for human use. Half of China's rural poor live in the basin areas of
these rivers.
China's deputy environment minister, Zhu Guangyao, said in June that dealing
with pollution may cost the country as much as 10 per cent of its GDP, which was
£1.2 trillion last year.
Not everyone agrees with the gloomy prognosis, and some scientists say that
glaciers in the Himalayas have not drastically shrunk despite global warming and
are unlikely to melt away in coming decades. Zhang Wenjing, an expert on
glaciers, who also works at the Chinese Academy of Sciences, did not question
global warming, however, he said it would take perhaps centuries to melt the
dense ice packs that accumulate and creep down the Himalayas.
WWF believes glacier recession would first cause flooding, then, decades later,
reduce the flows of major rivers such as the Ganges, Mekong and Yangtze. This
would, WWF predicted, cause environmental problems for Nepal and parts of China
and India as irrigation and hydropower suffered.
"The world faces an economic and development catastrophe if the rate of global
warming isn't reduced," said Jennifer Morgan, the environmental group's climate
change programme director. "They need to work together on reducing CO2
emissions, increasing the use of renewable energy and implementing energy
efficiency measures."
The WWF ran a witness report by Ngawang Tenzing Jangpo, the Abbot of Tengboche
monastery, the most revered monk in Khumbu, Nepal. "The temperature of the earth
is rising. It is not natural," said the abbot, who has lived in Khumbu for over
30 years and witnessed floods from lakes bursting with glacial meltwater.
"The Sherpas of Khumbu may not know everything, but they are suffering the
consequences of the people's greed. We mountain people should be careful and
take precautions. If we don't save Khumbu today our fresh water will dry up and
the problem will be impossible to solve in the future."