What is important here is not whether there is loss of ice in the Arctic but rather whether or not this is somehow unprecedented and if so what is the direct link to AGW theory.
It is fairly well documented that Ellesmere Island ice shelves have been breaking up throughout the 20th century, well before the recent warming from the mid seventies to present.
Jefferies, M.O., 1986, Ice Island Calvings and Ice Shelf Changes, Milne Ice Shelf and Ayles Ice Shelf, Ellesmere Island, N.W.T., Arctic, V. 39, p. 15-19
indicated that :
..the largest observed ice island calving occurred at Ward Hunt Ice Shelf where almost 600 km2 of ice broke away at some time between August 1961 and April 1963.
Note this was a relatively cool period with average temperatures having dropped from their high point in the late thirties (when they were close to current average temps). He also noted that 48km2 of calving occurred on the Ayles and Milne Ice shelves between 1959 and 1974. The important point is that the current ice extent is about 10% of what it was at the turn of the century, most of the calving occurred prior to the recent warming in the latter part of the 20th century.
An important point is that satellite coverage did not commence until 1978 so actual measures of sea ice extent prior to that are poorly constrained. What we do know is that the Northwest passage was navigated quite easily at the turn of the 20th century (Amundsen in 1905) and again in the early 1940’s whereas that has not been possible in the intervening years. That would mean that the sea ice extent has probably fluctuated quite considerably throughout the entirety of the 20th century. We also know that the current Ward ice shelf formed during the cooling period after the Holcene warm event and prior to that warm event the area was covered by ice. We also need to keep in mind that the disintegration of ice shelves can have a number of underlying mechanisms other than climate change including wind, wave and tidal action.
Tying anything that is going on in the Arctic or for that matter Antarctic to AGW theory requires some particular special pleading I think. Occam’s razor principle would suggest “natural variability” as the most reasonable plea given the history.