COPENHAGEN: Leading Chinese scientists have laid out challenges of climate change to China's sustainable development, saying most of the climate-related disasters known to the world have all occurred in China and extreme heatwaves could hit China more frequently.

In the past 50 years, extreme weather events have undergone great changes in frequency and intensity, and temperatures are expected to continue to rise in the 21st century, Luo said.

Elaborating on the changes in extreme weather events, the Chinese scientist said heatwaves in summer have increased in China, especially since 1998, and the number of days with temperatures above 35 degrees has risen above average levels for many years.

He also said regional drought has also become more serious in China, especially north China in the past two decades. The frequency and scope of and loss from the droughts have been unprecedented since 1886, he added.

The occurrence of strong precipitation has also increased in China, Luo said, adding the past two decades have been a period of frequent flooding since the 1950s in the Yangtze River and the Huaihe River.

Extreme heatwaves might become more frequent in the 21st century, and therefore could bring greater loss to sustainable development, Luo said.

Lin Erda, a professor of the Chinese Academy of Agricultural Sciences, said the negative effects of climate change on agriculture in China have begun to emerge. Temperature increases in the north, northwest and southwest of China have put strains on food production in the past two decades.

If drought hits northeast China frequently, agricultural loss in that region could increase by 7 percent by 2030, whereas in north China warming in winter could bring more freeze injury to crops, he said. Patterns for the occurrence of disease and insect will also change with rises in temperature, he added.

"In light of these changes, China's agricultural sector needs adjustment and adaptation to minimize loss from disasters and diseases," Lin said.