Whether or not the globe is warming, there is less Arctic sea ice in summer than formerly. Ships are beginning to sail across the northern side of Russia to make the transit, for example, from Hamburg to Shanghai - it is fewer miles.
This route north of Russia and Siberia will be more important for Europe than for the Americas. See an article in Spiegel Online International (in English) about the new Northeast Passage.
So far, the Northwest Passage hasn't been opening with any regularity, although Canada obviously has hopes, and Alaska too. I wouldn't mind making either passage in a cruise ship someday, a real adventure. The DrsC sailed in Antarctic seas ... an adventure we'll never forget, nor regret.
