You might have heard from the climate change deniers that this year will be the coolest globally this century. And that is true.

Newly released data from the UK Met Office shows that during the first half of 2008 the global temperatures was more than 0.1 Celcius cooler than any other year after 2000. The reason for this is La Nina, an ocean-atmosphere phenomenon that has a cooling effect on the earth.

But this doesn’t mean the deniers are correct about anything else. Scientists still expects that 2008 will be the 10th warmest year since 1850. And the UK Met Office says that the global temperatures will continue to rise again when La Nina eases away.

“The big thing that’s been happening this year is La Nina, which has lowered global temperatures somewhat,” said John Kennedy, climate monitoring and research scientist at the Met Office’s Hadley Centre.

“La Nina has faded in the last couple of months and now we have neutral conditions in the Pacific,” he told BBC News.

Dr Kennedy also said that “2008 will still be significantly above the long-term average,” and that “there’s been a strong upward trend in the last few decades, and that’s the thing to focus on.”

Even during the temporarily cooling effect from La Nina we see evidence that the rapid man-made warming continues. Images from National Aeronautics and Space Administration satellites show continued breakup of 2 of Greenland’s largest glaciers. According to Canadian authorities the Northwest Passage is navigable. Recently scientists warned that the Arctic could become ice-free during the summers as early as 2013. And just yesterday a huge chunk of ice shelf nearly the size of Manhattan broke away in Canada’s northern Arctic.