From the BBC website we learn that the expedition in question was the Catlin Ice Survey expedition. Readers may hear a bell ringing now and they would be correct. The weblog 'Watts up with that' have reported on the questionable character of this expedition from its very start (extensive coverage here).
With the publication of the results of the Catlin survey, Watts provides us with a top 10 of reasons not to trust the Catlin survey data. Included in those reasons is the tendency of the expedition to only travel on smooth ice. Which happens to be young ice, which happens to be thinner then older ice. The technical term for that seems to be 'navigational bias'. In more popular vernacular that is called 'crappy science'. And there was of course the embarrassing episode on the amateurishly fake 'telemetry data' on the expeditions participants.
A juicy bit of info is shared by commenter 'Ed Zuiderwijk' (a fellow Dutch-person?) who notes that
Catlin is an Insurance company specialising in selling cover against risk from “climate change”. Well, let’s say: it’s not an oil company.Tells you al you need to know about the import of the findings from Catlin Arctic Survey, doesn't it? More on sponsors paying for the Catlin Ice Survey can be found here. If this is the sort of sort of people that the Climate Hype depends on for its survival, I'd say the hype is truly over.