This year is set to be about the 10th warmest since records began in the 19th century, according to Phil Jones, a leading British climate scientist — see story here.

But does that confirm a long-term trend of global warming, stoked by human emissions of greenhouse gases, or show that it has stalled? The warmest year on record is now a while ago, in 1998.

Jones, head of the Climate Research Unit at the University of East Anglia, has no doubt that the underlying trend is still up — 1998 was an unusual year when global temperatures were boosted by an El Nino weather event in the Pacific Ocean. And this year, the opposite La Nina effect is cooling the planet.

(Among signs of a cooler 2008, some high Alpine ski resorts in Switzerland have opened early…)

And Jones says that the world’s thermometers may also be underestimating temperature rises because the Arctic — visibly warming since summer ice shrank in 2007 to the smallest since satellite measurements began in the 1970s – is pretty much excluded. That’s because there’s a lack of records from 1961-90, the benchmark years for judging current global warming, because ships didn’t go there.