Global average for 2008 should come in close to 14.3C, but cooler temperature is not evidence that global warming is slowing, say climate scientists























This year is set to be the coolest since 2000, according to a preliminary estimate of global average temperature that is due to be released next week by the Met Office. The global average for 2008 should come in close to 14.3C, which is 0.14C below the average temperature for 2001-07.

The relatively chilly temperatures compared with recent years are not evidence that global warming is slowing however, say climate scientists at the Met Office. "Absolutely not," said Dr Peter Stott, the manager of understanding and attributing climate change at the Met Office's Hadley Centre. "If we are going to understand climate change we need to look at long-term trends."

Prof Myles Allen at Oxford University who runs the climateprediction.net website, said he feared climate sceptics would overinterpret the figure. "You can bet your life there will be a lot of fuss about what a cold year it is. Actually no, its not been that cold a year, but the human memory is not very long, we are used to warm years," he said, "Even in the 80s [this year] would have felt like a warm year."

And 2008 would have been a scorcher in Charles Dickens's time - without human-induced warming there would have been a one in a hundred chance of getting a year this hot. "For Dickens this would have been an extremely warm year," he said. On the flip side, in the current climate there is a roughly one in 10chance of having a year this cool.

The Met Office predicted at the beginning of the year that 2008 would be cooler than recent years because of a La Niña event - characterised by unusually cold ocean temperatures in the equatorial Pacific Ocean. It is the mirror image of the El Niño climate cycle. The Met Office had forecast an annual global average of 14.37C.

Allen was presenting the data on this year's global average temperature at the Appleton Space Conference at Rutherford Appleton Laboratory, near Didcot yesterday. The 14.3C figure is based on data from January to October. When the Met Office makes its formal announcement next week they will incorporate data from November. "[The figure] will differ from it, but it won't differ massively," said Stott, "We would expect the number to go up rather than down because the early parts of the year were still under the La Niña conditions."

Assuming the final figure is close to 14.3C then 2008 will be the tenth hottest year on record. The hottest was 1998 - which included a very strong El Niño event - followed by 2005, 2003 and 2002. The data are a combination of measurements from satellites, ground weather stations and buoys which are compiled jointly by the Hadley Centre and the Climate Research Unit at the University of East Anglia.

In March, a team of climate scientists at Kiel University predicted that natural variation would mask the 0.3C warming predicted by the Intergovernment Panel on Climate Change over the next decade. They said that global temperatures would remain constant until 2015 but would then begin to accelerate.