"The precise causes of these phenomena aren't easy to determine on their own," Dong told Reuters of meteorological disasters that have caused 160 billion yuan (US$20 billion) worth of damage this year.

"But we know the broad background is global warming. That's clear. It's a reminder that global warming will bring about increasingly extreme weather events more often."

A study issued by China's chief climate scientists last year predicted that mean temperatures across China were likely to climb, forcing major changes in rainfall, desertification, river flows and crop production.

Yet even as China approaches the United States as the world's largest producer of the manmade greenhouse gases that trap heat in the atmosphere, Beijing is set against mandatory ceilings on its emissions, experts said.

"China's preoccupation is economic development and growth," said Paul Harris, of Lingnan University in Hong Kong, who studies climate change policy.

"It seems Chinese policy-makers are beginning to take warnings about global warming on board. But they certainly don't want to sign on to compulsory caps."

Global warming may increase rainfall in China's north, but increased temperatures and evaporation there are likely to offset much or all of that, Lin Erda, a climate expert at the Chinese Academy of Agricultural Sciences, told Reuters.

Without corrective action, nationwide agricultural production was likely to fall between 5 and 10 percent, he said.

UNUSUAL CLIMATE SHIFT

With its vast and arid western half, China is no stranger to drought. But, unusually, this year's extreme heat and dry had struck the geographical basin enclosing Sichuan province and Chongqing municipality, said Dong.

Until now, that area has experienced a slight fall in average temperatures over past decades, possibly thanks to a protective umbrella of pollution or cloud.

But this year much of Sichuan and Chongqing has suffered record-breaking hot days and the lowest rainfall for nearly 60 years, and on Sunday Sichuan forecast another burst of 38 degrees Celsius (100 degree Fahrenheit) days and withering drought.

Whether this shift was a one-off or augured a long-term change remained to be seen, said Dong. Part of the explanation appeared to lie in shrinking snow cover on the neighbouring Tibet-Qinghai plateau, he said.

But even as China feels the effects of global warming, it is unwilling to cap its greenhouse gas emissions, saying responsibility for tackling global warmings lies with developed countries that are -- per capita -- still much bigger polluters.

China is a signatory to the Kyoto Protocol, the international treaty intended to rein in greenhouse gas emissions. But as a developing country, China is exempt, for now, from the limits on greenhouse emissions that wealthy countries are supposed to abide by.

"We're willing to limit and transform industry and our energy structure by ourselves," Dong said.

"But as a matter of fairness, it has to be voluntary, not mandatory, because we're a developing country."