China's glaciers have shrunk by thousands of square kilometres over the past 30 years as a result of climate change, state-run media reported Wednesday.

The Qinghai-Tibet plateau in western China has seen its glaciers shrink by 15 percent, or 8,000 square kilometres (3,089 square miles), the official Xinhua news agency cited the Chinese Academy of Sciences (CAS) as saying.

Glacier melt in the region, which includes the Chinese portion of the Himalayas, has accelerated since the 1990s, the report cited researchers as saying, the latest sign of the impact of climate change in the region.

The report cited CAS researcher Kang Shichang as saying that "more and bigger cracks" have appeared in ice on Mount Everest, a sign of "rapidly melting glaciers".

The Qinghai-Tibet plateau covers the area China calls the Tibetan Autonomous Region as well as highland parts of neighbouring provinces.

Kang added that over the long term the glacial melt could substantially reduce the flow into several of Asia's main rivers, which originate on the Tibetan plateau.

Climate change poses a major threat to water security worldwide, according to a March report by the UN's Intergovernmental Panel on Climate Change (IPCC).

The panel said last year it was 95 percent certain that humans were the main cause of increases in average global temperatures, which it predicts will rise by between 0.3 and 4.8 degrees Celsius (0.5 to 8.6 Fahrenheit) by the end of this century.

The report said the increase could be limited to two degrees C (3.6 degrees F) if a major change in energy sourcing and consumption took place.

The IPCC has said that Himalayan glaciers will shrink by nearly half if global average temperatures rise by 1.8 degrees C by 2100.