Brent Stephenson / Calm conditions with sea ice in the Lemaire Channel. Antarctic Peninsula, Antarctica, December.

Chadden Hunter / Person standing infront of long icicles, outside volcanic ice cave, Mount Erebus, Antarctica. Taken on location for BBC Frozen Planet series, 2009

Andy Rouse / Waterfall from ice cliffs with ice-cap stretching into the distance. Austfonna Polar Ice Cap, Svalbard, Norway, August 2011.

Mark Hamblin / 2020VISION / Climbers on ascent of Cairn Lochan in winter, Cairngorms National Park, Highlands, Scotland, UK, January 2011

Jenny E. Ross / Polar Bear (Ursus maritimus) sub-adult male on cliff searching for eggs in Brunnich's Guillemot nests, as gulls look on from above. This unusual behaviour happens when when lack of sea-ice prevents t...

Kathryn Jeffs / Cliff at edge of tabular iceberg, Antarctica, February 2009, Taken on location for BBC Frozen Planet series

Frederique Olivier / Weddell seal (Leptonychotes weddellii) pup on ice beside mother, Antarctica, Taken on location for the BBC series, Frozen Planet.

Jeff Wilson / Frozen Planet team tent at Lake Hoare Camp, Dry Valleys, Antarctica, December 2009. Taken on location for the BBC series, Frozen Planet.

Jeff Wilson / Emperor penguin (Aptenodytes forsteri) adults and chicks in colony beside ice cliff, Cape Crozier, Antarctica, November 2009. Taken on location for BBC series, Frozen Planet, Spring.

Bryan and Cherry Alexander / Iceberg and grease ice reflecting in the Weddell Sea at sunset. Antarctica, October 2006.

Brent Stephenson / Steep rock walls of the Tracy Arm, carved out by glacial action over millions of years. Alaska, United States, July 2010.

Bryan and Cherry Alexander / Icebergs frozen in frazil ice (ice crystals) at beginning of winter. Northwest Greenland, 1991.