New US government figures, presented to international experts in Washington this month and confirmed by British scientists, show that the world climate between March and October this year was hotter than at any time since records began. This finding - following a blistering summer from Toledo to Tokyo, and a rapid spread of flowers and grasses in Antarctica exclusively reported in the Independent on Sunday in September - is provoking renewed concern that global warming is resuming after a brief lull.
The lull was caused by the massive volcanic eruption of Mount Pinatubo in the Philippines in the summer of 1991, but the new research indicates that now the effects of the volcano are dying away.
The research, by the US government's Climate Prediction Centre, shows that global average temperatures between March and October were about 0.4 of a degree centigrade above normal - a big rise in climatic terms - making it the hottest period since their records began in the 1860s.
Dr Philip Jones of the Climate Research Unit at the University of East Anglia says that he has obtained similar results. He says that, if the mild weather continues through December, this year could be the third warmest ever: had it not been for a particularly cold January and February it would be set to be the hottest on record.
He adds that if next year starts mildly it could be a new record-breaker. Dr Chris Folland of the Meteorological Office agrees: ''Temperatures are rising as the effect of Mt Pinatubo diminishes.''
The eruption, which threw 20 million tons of sulphur into the atmosphere in June 1991, had an immediate effect on climate. 1990 was the hottest year ever recorded and 1991 was set to surpass it, but temperatures dropped as the sulphur filtered out sunlight.
In the end, 1991 was only the second hottest year ever measured, and 1992 was cooler. But the world has been heating up again in 1993 and 1994 as the particles of sulphur gradually fall to earth.
Geraldine Bedell, page 21