It’s going to take a good while before the passage becomes really viable and at that point there’s nothing anyone (especially not the Canadian government) will be able to do to prevent some heavy environment impact. (I think it’s a relatively sure bet that a ship will at some point spill something nasty while traversing the northwest passage.) However, right now the possibility of an open passage raises the geopolitical question of “who’s in charge?.” And, quite honestly, given the likely candidates and my current knowledge (as always, admittedly limited) I’d prefer see the answer to remain Ottawa.