"Since 1976, the global average temperature has risen at a rate approximately three times faster than the century-scale trend," Godwin Obasi, secretary general of the World Meteorological Organization (WMO), said at a conference on climate change.

The year 1998 was the hottest since records were first made in certain parts of the world in 1860, followed by 2002, he said.

"We are also certain that the atmospheric concentration of carbon dioxide (CO2) has increased from 280 ppm (parts per million) in 1750 to 370 ppm by the end of 2001.

"Today's CO2 concentration has not been exceeded in the past 420,000 years and not likely during the past 20 million years," Obasi said.

The burning of fossil fuels produces CO2, long seen as the main "greenhouse gas" causing global warming.

Obasi also said the world has witnessed a growing number of "unprecedented extreme weather events," such as tropical cyclones, severe floods and droughts that have resulted in considerable loss of life in many countries including China, host of the ongoing conference.

Northern China, like Brazil, South Africa and many areas in the Middle Eastern and Central Asia are all suffering from record-breaking droughts, he said.

The ongoing symposium aims to improve meteorological forecasts and the impact of climate change on "the public and private sectors, particularly as it relates to environmental protection and sustainable development."

The conference was opened by newly appointed Chinese Vice Premier Hui Liangyu, who is in charge of China's agricultural issues.

SPACE.WIRE