OSLO, Nov 11: This year is on track to be about the 10th warmest globally since records began in 1850, but gaps in Arctic data mean the world may be slightly underestimating global warming, a leading scientist said on Tuesday.

A natural cooling of the Pacific Ocean, known as La Nina, kept a lid on temperatures this year, despite an underlying warming trend, said Phil Jones, director of the climatic research unit at the University of East Anglia, in England.

“This year is about 10th,” he said in a telephone interview. “La Nina in the Pacific lasted longer than we envisaged.”

Jones’s unit is one of the main sources of global climate data for the United Nations.The warmest year on record was 1998, followed by 2005 and 2003, with other years this century closely bunched. Tenth place would make 2008 the least warm since 1999.

The update marginally cools an estimate from January, when Jones’s unit and the British Met Office (Britain’s meteorological service) estimated that 2008 would be “another top 10 year”, near the bottom of the ranking.

The U.N. Climate Panel says human emissions of greenhouse gases, mainly from burning fossil fuels, are blanketing the planet. Rising temperatures will bring more floods, heatwaves, more powerful storms and rising sea levels, it says.

Jones said temperature records may fractionally underestimate warming because of gaps in measurements in the Arctic for 1961-90, the benchmark years for judging change, and problems in verifying ocean temperatures.

“The world is probably a little warmer than we are measuring,” he said.

ICE THAWS: Arctic sea ice shrank to a record low in summer last year, and almost matched the low again this year. UN studies say the region may be warming twice as fast as the world average.

Ships are travelling more often in the Arctic and “now there are temperature measurements coming back. But we can’t use the data because we don’t have the 1961-90 averages”, he said.—Reuters