In 2007, Professor Wieslaw Maslowski from the Naval Postgraduate School, said this :

“Our projection of 2013 for the removal of ice in summer is not accounting for the last two minima, in 2005 and 2007,” the researcher from the Naval Postgraduate School, Monterey, California, explained to the BBC.

“So given that fact, you can argue that may be our projection of 2013 is already too conservative.”

BBC NEWS | Science/Nature | Arctic summers ice-free ‘by 2013’

Two years later when it was obvious he was wrong, he tried to blame it on Al Gore.

However, the climatologist whose work Mr Gore was relying upon dropped the former Vice-President in the water with an icy blast.

“It’s unclear to me how this figure was arrived at,” Dr Maslowski said. “I would never try to estimate likelihood at anything as exact as this.”

Inconvenient truth for Al Gore as his North Pole sums don’t add up – Times Online