Polar Bear Habitat Designated as Critical

From the NY Times "The Interior Department on Thursday proposed designating more than 200,000 square miles of land, sea and ice along the northern coast of Alaska as critical habitat for the shrinking polar bear population."

The real question is how are they going to enforce it? It makes sense that the habitat is important but if we are to believe a good chunk of the science out there then there is not one thing causing the sea ice to melt but many. It isn't one power plant, one car, etc. etc. etc. but the combination of many things some of which can't be regulated. What happens if these things are regulated but the sea ice moves locations? This will be an interesting story to track.