2007 Warmest year..?

LONDON -- A resurgent El Nino and persistently high levels of greenhouse gases are likely to make 2007 the world's hottest year ever recorded, British climate scientists said Thursday.

Britain's Meteorological Office said there was a 60 percent probability that 2007 would break the record set by 1998, which was 1.20 degrees over the long-term average.

"This new information represents another warning that climate change is happening around the world," the office said.

The reason for the forecast is mostly due to El Nino, a cyclical warming trend now under way in the Pacific Ocean. The event occurs irregularly -- the last one happened in 2002 -- and typically leads to increased temperatures worldwide.

While this year's El Nino is not as strong as it was in 1997 and 1998, its combination with the steady increase of temperatures due to global warming from human activity may be enough to break the Earth's temperature record, said Phil Jones, the director of the Climatic Research unit at the University of East Anglia.

"Because of the warming due to greenhouse gases, even a moderate warming event is enough to push the global temperatures over the top," he said.

"El Nino is an independent variable," he said. "But the underlying trends in the warming of the Earth is almost certainly due to the release of carbon dioxide into the atmosphere."