There's a very odd article at WUWT by Jim Steele about Antarctic sea ice (archived here, latest here). He started off the article saying he'd just read a new paper about Arctic sea ice. The paper, by Neil Swart and colleagues was published in Nature at the end of January.
The introduction to the paper sets the scene:
Internal climate variability can mask or enhance human-induced sea-ice loss on timescales ranging from years to decades. It must be properly accounted for when considering observations, understanding projections and evaluating models.
The scientists were looking at trends in Arctic sea ice in recent years. What they were looking at in particular was the extent to which internal climate variability can affect the trend. That is, how much of the ups and downs in Arctic sea ice could come from internal variability compared to the underlying decline from enhanced greenhouse warming.
The main message from the paper, I think, is that Arctic sea ice decline is not necessarily underestimated by climate models. The recent big dips of 2007 and 2012 could be natural variability. It's difficult to tell.