I thought it was worth reviving this thread as we're now well into 2013 and only a month away from September, when the minimum Arctic sea ice occurs. Bob (the blogger who is linked to in the starting post of the thread) was effectively predicting Arctic sea ice to disappear by 2020, so we can now see how that prediction is working out.
The latest results for the PIOMAS data (up to July 2013) are given on this link:
It looks like the volume of sea ice, which is what the PIOMAS computer model estimates, has gone back to 2010 levels.
Most people prefer to use the area of sea ice extent as the parameter for monitoring Arctic sea ice loss, which is easier to measure experimentally, and the latest results for that are given on this link:
On the subject of Arctic sea ice loss, there was a fairly well-publicised warmist prediction about this made back in 2007 which is virtually certain to fail. The prediction by a US computer modelling group led by Wieslaw Maslowski was that the Arctic would be ice free by the summer of 2013, described in this link:
The Arctic sea ice minimum occurs in September, around the Sept 21st equinox. I think in the US they take the Northern hemisphere summer as being from June 21st to Sept 21st, whereas the meterologists' convention is to take it as being the months of June, July and August. There is a British convention that summer is mid-May to mid-Aug, which accounts for the oddity that Midsummer's day corresponds to being near the end of June, June 24th.
This prediction was mentioned in the speech by Al Gore when he accepted the 2007 Nobel Peace Prize:
"Last September 21, as the Northern Hemisphere tilted away from the sun, scientists reported with unprecedented distress that the North Polar ice cap is "falling off a cliff." One study estimated that it could be completely gone during summer in less than 22 years. Another new study, to be presented by U.S. Navy researchers later this week, warns it could happen in as little as 7 years.
Seven years from now."
Gore has got the figure slightly wrong - it was 6 years rather than 7 years, but he may have changed it to 7 just to fit in with some other mentions of 7 years in the speech.
I just noticed on the WUWT blog that they've put up something called "The Maslowski Counter" which counts down the remaining days for the prediction to be fulfilled.