Melting ice around the Antarctic may paradoxically be preventing ice melt on the ocean surface. ->
Arctic nations need to prepare for years when extreme conditions lead to widespread polar bear malnutrition. ->
The start of Arctic spring/summer sea ice melt has begun; tying this year's furthest winter extent south with 2006 as the lowest on record.
Arctic summer ice coverage may hold strong for a decade, despite global average temperatures rise.
Disappearing sea ice could mean fewer and fewer polar bear cubs.
Disappearing sea ice may affect mercury levels in Arctic waters.
Observations by the European Space Agency's CryoSat-2 satellite suggest that the route may be ready for summer sea traffic sooner than expected.
Researchers have tracked a polar bear swimming for nine straight days, but losing 20 percent of her body mass, and her young cub, in the process.