That's how few square miles of Arctic Ocean ice were left after this summer's melt -- compared to 1.61 million in 2007, the previous low.

Less white ice means more dark water exposed to the sun, causing our warming planet to absorb more heat. That can lead later to higher sea levels. It raises questions of how to regulate increased fishing and drilling in ice-free waters. The UN Convention on the Law of the Sea is guiding discussions of mineral rights. Our nation hasn't signed it; the melting ice is another reason we should.