Simply put, the IPCC's climate models and experts are unable to predict cloud formation and coverage, which makes accurately predicting climate conditions an impossible task.
As a result, the models have huge problems with predicting actual polar sea ice coverage and albedo characteristics - a continuing major fail that shreds the IPCC's creditability as a reliable source for climate fearmongering prognostications.
This latest study confirms that the state-of-the-art climate models have proven to be no better at predicting Arctic clouds and sea ice than their grossly inaccurate predecessors.
And as these plots (source) of polar sea ice indicate, the global sea ice area and extent exhibit an increasing trend that is the polar opposite of the IPCC's those fabled "expert" predictions. (bad pun intended)
Previous climate-model and peer-reviewed postings.