GEOLOGY

Detailed explanation-1: -The Arctic is warming about twice as fast as the global average, causing the ice that polar bears depend on to melt away. Loss of sea ice also threatens the bear’s main prey, seals, which need the ice to raise their young.

Detailed explanation-2: -Polar bears are moving to land on the north coast of Alaska because the sea ice is melting and no longer connects to shore. This separates the bears from their preferred hunting grounds, the sea ice. With less sea ice, polar bears cannot hunt for food as often, and so they wind up with less to eat.

Detailed explanation-3: -More solar energy is absorbed at the surface and ocean temperatures rise. This begins a cycle of warming and melting. Warmer water temperatures delay ice growth in the fall and winter, and the ice melts faster the following spring, exposing dark ocean waters for a longer period the following summer.

Detailed explanation-4: -The warmer temperatures are having impacts in the Arctic region. Sea ice is melting, frozen ground (called permafrost) is thawing, and habitat is shrinking for wildlife that rely on cold temperatures. Arctic sea ice cover is shrinking at a rate of 13% per decade.

Detailed explanation-5: -The main reason polar bears are reliant on sea ice is that they feed on seals which inhabit ice-filled waters. The two main species are ringed seals and bearded seals. Species such as harp seals and hooded seals are also important in some areas.