(Adds report on glaciers melting) BEIJING, Jan 5 (Reuters) - China's largest lake, holy to Tibetans but suffering from global warming and desertification, may vanish in two centuries even as the government pledges $870 million to stop it shrinking, Xinhua news agency said on Friday. Desertification had been brought about by overgrazing around Lake Qinghai, in the remote western province of Qinghai, which is at the crossroads of several bird migration routes across Asia and is about 360 km (220 miles) in circumference. Overfishing had also reduced the catch of the unusual scaleless naked carp in the lake to just 10 percent of what it was 40 years ago, Xinhua said on its Web site (www.xinhuanet.com). Over the next 10 years the government has pledged 6.8 billion yuan ($871.4 million) to address the lake's environmental problems, Xinhua added. "Experts predict that if it continues shrinking at its present rate, the lake, which on average today is 18 metres (59 ft), could completely disappear in 200 years time," it said. At the same time, glaciers on the nearby Qinghai-Tibet plateau had shrunk 131.4 square km annually in the last 30 years, Xinhua cited a report by the China Geological Survey Bureau as saying. "What that means is that an area of glacier equivalent to twice the size of the Beijing downtown area disappears every year," it said. "A further 13,000 square km of glacier -- nearly 28 percent of the total glacier area and equivalent to twice the area of Shanghai municipality -- will disappear by 2050 if no protective measures are taken," the report added, Xinhua said. ($1=7.803 Yuan)
