Dr. Pokrovsky also finds good agreement between the ~60 year AMO cycle and Arctic ice extent:
He also finds similar periodicity in the PDO during the instrument era (first graph) and from paleoclimate reconstructions (second graph).
And comes to the following conclusions:
His findings are also in agreement with several other authors who have identified the ~60 year natural climate cycle from a variety of paleoclimate indicators and analysis of ocean cycles. Yet, the IPCC doesn't consider the very important ocean oscillations at all in their climate models, preferring to blame almost all climate change upon man-made CO2. As Dr. Roy Spencer points out in his new book, almost no scientific work is being done to examine these huge natural forcings of climate change, since there is little grant funding for anything other than studies of anthropogenic climate change.