Global temperatures for 2000-2008, the first eight years of this millennium, are almost 0.2º Celsius warmer than the average for the decade 1990-1999. The 10 warmest years on record have occurred since 1997, revealed climate scientists at met office’s Hadley Centre and University of East Anglia.

The scientists at UK’s national weather service and University of East Anglia’s climatic research unit maintain the global climate record for the World Meteorological Organisation.

Globally temperature was 0.31º Celsius above the 1961-90 average. In the northern hemisphere, the mean temperature was 0.51º Celsius above average (eighth warmest on record) and in the southern hemisphere it was 0.11º Celsius above average (20th warmest).

The global mean temperature has slightly reduced compared to earlier years in this century partly because of the La Nina that developed in the Pacific Ocean during 2007, the scientists explained.

La Nina events typically coincide with cooler global temperatures and 2008 is slightly cooler than the norm under current climate conditions. "The most important component of year-to-year variability in global average temperatures is the phase and amplitude of equatorial sea surface temperatures in the Pacific that lead to La Nina and El Nino events," Prof. Phil Jones of East Anglia University said.

Human influence has led to increase in temperature, said Dr Peter Stott, head of climate monitoring and attribution at the met office’s Hadley Centre.

"Human influence, particularly emission of greenhouse gases, has greatly increased the chance of having such warm years. Comparing observations with the expected response to man-made and natural drivers of climate change it is shown that global temperature is now over 0.7º Celsius warmer than if humans were not altering the climate," he added.

"Globally this year would have been considered warm, even as recently as the 1970s or 1980s, but a scorcher for our Victorian ancestors," Dr Myles Allen of Oxford University said.