Listening to another article, it appears that it's not just the arctic that's far ahead of the climate models. Most models predict that the tropics will expand by 2 degrees of latitude by the end of this century, but there's a report being presented at the Bali climate conference that says that amount of expansion has already happened.
By the way, the Bali conference which runs for two weeks, is the start of the process of negotiating a successor to the Kyoto Accord. The hope is that negotiations will be concluded by 2009, while Kyoto expires in 2012. But even the person leading this conference advised the BBC interviewer to keep his expectations of "success" extremely low. Even the perosn chairing the conference, in other words, doesn't expect much to be accomplished there.