Professor Laurence Smith, in his book "The World in 2050: Four Forces Shaping Civilization's Future" published by Penguin in 2010, eISBN: 978-1-101-44352-1 addresses how shipping patterns might evolve as arctic ice melts.
He posits that rather than seeing an explosion in trans arctic shipping, we shall instead see vastly increased intra arctic shipping. His reasoning is that until such a time as there is zero ice floating around in the arctic, low certainty and insurance rates will still be to high to justify extensive trans arctic voyaging. However, the cost and importance of shipping to a from arctic ports and communities is high enough to justify the high cost and reduced reliability of these routes..