8. Western Hudson Bay, Canada

Western Hudson Bay, Canada [huanqiu.com]

For most of the year, the polar bears wander around the frozen Hudson Bay and feed on seals. In the western area of Hudson Bay, snow will start to melt in late spring. At that time, polar bears will go into hibernation, living off self-reserved fat, until the sea freezes again. But now the melting time in this area advances almost three weeks than it did in the early 1970s, limiting the endangered bears' access to food.