BEIJING, May 6 (Reuters) - China's controversial railway to
the remote and restless mountainous region of Tibet could be
threatened by global warming, which may melt the permafrost on
which the tracks are built, state media said on Wednesday.

"In Tibet, the mercury has climbed an average of 0.32 degrees
Celsius every decade since records began in 1961," China
Meteorological Administration head Zheng Guoguang was quoted as
saying by the official Xinhua news agency.

"This is much higher than the national average temperature
rise of 0.05-0.08 degrees Celsius every 10 years," Zheng added,
speaking at a meeting in the Tibetan regional capital of Lhasa.

Tibet, being so high, acted as a "magnifier" for global
warming, Zheng said.

"The impact of global warming has accelerated glacial
shrinkage and the melting glaciers have swollen Tibet's lakes,"
Zheng added. "If the warming continues, millions of people in
western China would face floods in the short term and drought in
the long run.

"In the worst case, such warming could cause permafrost to
melt and threaten the plateau railway linking Tibet with
(neighbouring) Qinghai province," the report paraphrased him as
saying.

Beijing has said it wants to combat climate change yet ensure
China's economic development is unimpeded.

Xinhua said the government believes the railway will be safe
to use for the next 40 years if the thaw continues at its present
speed.

Over the last two decades it has spent more than 1 billion
yuan ($146.6 million) reinforcing the main highway to Tibet,
where the permafrost is also melting, Xinhua added.

China says the 30 billion yuan rail line, opened in 2006 and
passing through towering mountains and vast deserts, will help
bring economic development to ethnically distinct Tibet.

Tibetan activists, however, say it speeds the immigration of
Han Chinese to Lhasa and the plateau, and allows increased
exploitation of Tibet's significant mineral resources.
($1=6.822 Yuan)
(Reporting by Ben Blanchard; Editing by Nick Macfie)