(Slate::Bad Astronomy) – Phil Plait:
It’s not hard to see that over the past few years, the oldest ice has melted away, and over time the ice gets younger. That’s not good: Older ice is thicker and tends to hang around longer; young ice is generally thinner and melts away every summer. That means that the year-round amount of ice is dropping, and dropping rapidly. As the Arctic warms, its ability not just to form ice but to keep it wanes. …