This is the largest ice shelf so far. I don't expect that scientists will show much concern until another ice shelf starts cracking off. 

But when the ice on land in the area of the shelf starts to slide in the water and levels rise by about 4 inches then we'll start seeing concern especially in the equatorial areas where the buildup of water levels is great. I don't think the US will start worrying until the ocean level effects our Shores.

Europe is concerned because for years now, the ice on Greenland has started accelerating its disappearance.