jmw: in Canada I believe there is no dispute whatsoever that Arctic ocean ice cover is disappearing. Just ask the Inuit in the Canadian north. They live there, year-round, and are routinely seeing species now that they've never seen before, as well as having their hunts disrupted by thin sea ice. So it's not just the polar bears, nor can you put too much faith in one "expedition".
There are two questions, is arctic ice disappearing more or less than corresponding periods? Most of the discussions relate to coverage not thickness.
Secondly, is it normal natural cyclic behaviour or did man cause it?
I'd say there is a dispute about what is seen and how it is interpreted.
A citation or link to an Inuit report would be nice.
There are a number of ongoing techniques for measuring the ice thickness including satellite, radar, laser interferometry and so on.
The Catlin "survey" came back with 39 data points across a shorter 450km(?) route than planned and which depended on bore holes once their radar didn't work.
There own web site admits a bias because it is easier going for the explorers to travel on new (one year) ice which is flatter easier going and preferred for camping.
One survey shouldn't be relied, I quite agree.
And one which collects so little data as this is a case in point so would you please direct your comment to the BBC, the Daily Telegraph Environment Correspondent and a few others who have taken the report and blown it up without doing a sanity check against the various other data sources.
In either case, please note that I have posted links. I am not the scientist here but an interested observer.
JMW