A new study published in the journal Nature identified a possible cause for this discrepancy. It identifies a natural, cyclical flow of atmospheric energy around the Arctic Circle. A team of researchers, led by Rune Graversen of Stockholm University, conclude this energy flow may be responsible for the majority of recent Arctic warming.
The study specifically rules out global warming or albedo changes from snow and ice loss as the cause, due to the "vertical structure" of the warming ... the observed warming has been much too weak near the ground, and too high in the stratosphere and upper troposphere.
This study follows hot on the heels of research by NASA, which identified "unusual winds" for rapid Arctic ice retreat. The wind patterns, set up by atmospheric conditions from the Arctic Oscillation, began rapidly pushing ice into the Transpolar Drift Stream, a current which quickly sped the ice into warmer waters.
A second NASA team, using data from the the GRACE (Gravity Recovery and Climate Experiment) satellite, recently concluded that changes in the Arctic Oscillation were "mostly decadal in nature", rather than driven by global warming.
quote: But the models we have right now are our best tools to explain what is happening and what will happen in the future.
quote: The last 25 years constitute a period of more complete and accurate observations and more realistic modeling efforts. Yet the models are seen to disagree with the observations. We suggest, therefore, that projections of future climate based on these models be viewed with much caution.