Zhu Changhan, chief weather expert of China National Climate Center, said the average temperature in most regions last year was close to the levels of past years or a little bit higher than previous.

"But, in general, the pattern did not generally change. It is just that last year witnessed a spate of more extreme weather," said Zhu.

Chinese residents have experienced a roller coaster ride of temperature changes last year, ranging from a warm winter at the beginning of the year and a scorchingly hot summer, to an unprecedented cold spell featuring continuous snowfalls at the end of the year.

The first month of 2002 was the warmest winter month since 1949, with the average temperature hitting new highs.

In a sharp reversal, snow fell heavily in northern China from December 18 to 25, with some regions experiencing the lowest temperatures in 50 years.

Zhu said in an interview in yesterday's People's Daily that such extreme weather and ensuing natural disasters have major implications for environmental protection, food security and water supplies.

Furthermore, these problems also impact people's daily life and work, and particularly lead to changes in the human body's physiological functions.

Extreme weather hits senior citizens or people in poor health hardest as it may increase their chances of contracting or aggravating diseases, said Zhu.

However, Zhu said the El Nino phenomenon was not the major cause of such extreme changes in the weather.

"El Nino can be blamed for the average high temperatures last year, but it was not enough to provide an explanation for extreme weather changes occurring over a short period of time and in a limited area," he said.

The El Nino phenomenon is caused by abnormal temperature increases in tropical waters off the west coast of South America, which lead to global weather and climate anomalies. It affects China every two to seven years.

In another development, some weather researchers have predicted that El Nino will hit China in April or May this year.

Cai Yi, a researcher at the National Research Center for Marine Environment Forecasts in Beijing, said northern China will probably experience high temperatures and drought this summer, while southern China is likely to be affected by flooding.

It is forecast El Nino will affect China three times in the period between this year and 2008, according to Cai.

(China Daily January 21, 2003)