Melting glaciers

Yao Tandong, China's leading glaciologist and Director of the Institute of Tibetan Plateau Research of the Chinese Academy of Sciences (CAS), is one of a small number of people who have witnessed global warming first hand. For over a decade, Yao has been conducting field research on his specialty of the ice core at the Qinghai-Tibet Plateau, the highest plateau in the world.

Shocked by evidence of the accelerated melting of glaciers in the region since the early 1990s, Yao recently announced his findings of the last 10 years: the retreating glaciers are accelerating; advancing glaciers are beginning to retreat; and even the ice cap on the world's highest mountain peak has begun thinning.

Nicknamed "the third pole," the Qinghai-Tibet Plateau is acknowledged as a barometer for global climate change. Meteorologists believe that changes on the plateau's ice cap and snow volumes will affect monsoon and rain patterns in China, as well as the climate change around East Asia and beyond.

Xu Ying of the CMA said while the global glaciers' retreat since the end of the Little Ice Age (1350-1850) seems normal, the worrisome phenomenon is the accelerated melting since the early 1990s, the warmest decade in human record. "This will subject tens of millions of people worldwide to mounting threats of more droughts, floods and lack of drinking water," she said.

A four-year, 10-million-yuan satellite remote sensing survey on the Qinghai-Tibet Plateau by the China Geological Survey Bureau shows that glaciers on the plateau have shrunk by 131.4 square km annually, twice the size of the Beijing downtown area. The survey shows that glaciers on the outskirts of the plateau have already decreased by 10 percent and those in the hinterland have shrunk by 5 percent.

Researchers said the melting of the glaciers has brought abundant water to the rivers, lakes and wetlands on the plateau and its surrounding areas in the short term. A study by the Chinese Academy of Sciences in 2004 indicated that the annual runoff of rivers in China's northwest, whose headstreams are supplied by the region's melting glaciers, had increased by 5.5 percent over the last 10 years.

"But as the glacier shrinkage accelerates, the plateau's total water storage will decrease rapidly," said Fang Hongbin, a remote sensing experts, told Xinhua News Agency.

Experts point out that since the plateau supplies the headstreams of many of the major rivers in East, Southeast and South Asia, the decrease of water storage in the region will have a significant impact on the economic and social development of China as well as neighboring countries.

Lin of the CAAS, who had conducted several field surveys to Tibet, told China Youth Daily that the accelerated melting of glaciers has caused the rise of water levels of local lakes, submerging pastures. But he said such a scenario will not be sustainable, as the withdrawal of glaciers will eventually lead to the shrinkage of these lakes. He said government leaders from Xinjiang Uygur Autonomous Region have been worried about the latest findings in the acceleration of glaciers' melting in Xinjiang, whose economic pillar of oasis farming and cattle-raising relies keenly on a steady water supply from glaciers.

Yao of the CAS warned that, "The full-scale glacier shrinkage in the plateau region will eventually lead to an ecological catastrophe." He referred to the long-term aftermaths of glaciers' shrinkage, including the draining of rivers, arid climate and worsening desertification in China.

"The melting of glaciers will lead to the exposure of microbes that have been buried under the ice cap for tens of thousands of years and the spread of microbes will pose potential dangers to human health," said Xu of the CMA.

More efforts needed from government

As the world's second largest emitter of carbon dioxide after the United States, China is gradually losing its edge of low per-capita emission against industrial countries, because of its backward and energy-consuming industrial equipment. CMA Director Qin Dahe predicted in 2004 that China was likely to become the world's largest emitter of CO2 by 2025 if no preventive measures were taken.