The Tuna Glacier in the Norwegian Arctic.
Field Assistant Lisa Strom stands on the surface of the frozen sea in front of the Tuna Glacier, which is part of the Svalbard archipelago in the northernmost part of Norway. Icebergs calve off the front of these glaciers but usually only during the summer. Glacier ice is formed from thousands of years of accumulated snowfall and has a distinctive blue color.
David Attenborough at the North Pole, April 2010.
Sir David Attenborough, host of the "On Thin Ice" episode and the BBC version of Frozen Planet, is standing on the frozen surface of the Arctic Ocean. The ice has been scoured clear of snow by the strong winds.
A walrus haul-out at Point Lay, Alaska.
Up until 2007, mother walruses in northwest Alaska and northeast Russia were known to always give birth on ice floes. Since 2007 however, there has been so little ice on the surface of the Arctic Ocean that the walruses have been forced to bring their calves to land. Haul-outs of many thousands of animals have been seen on both sides of the Bering Strait. It spells trouble for the walruses, first because many young animals get crushed to death in this melee of animals, but also because the adults have to swim further to find their feeding grounds off-shore.
A moulin on the Greenland Ice Sheet.
Camerawoman Justine Evans abseils into a moulin on the Greenland Ice Sheet. A moulin is a gigantic crack in the ice down which meltwater tumbles in the summer months. Scientists are interested in studying where this water goes because it is believed to be acting as a lubricant, causing the ice sheet to slide more quickly towards the sea.
Survey flying over the disintegrating Wilkins Ice Shelf.
The Wilkins Ice Shelf, a 200-meter thick sheet of floating fresh water ice larger than Jamaica, started to break up in 2008. Some of the resulting icebergs are over a kilometer long. Seven major ice shelves have broken up on the Antarctic Peninsula in the last 30 years in a wave that has been traveling southwards.
David Attenborough watches a ringed seal mother and pup, Svalbard, Norway.
Ringed seals are the favored prey of polar bears and pups are usually hidden away in lairs under the ice. Unusually low snowfall in the previous winter meant that the pups in this frozen fjord were exposed on top of the ice and hence particularly vulnerable to predation.
David Attenborough, Dr. Jon Aars and Magnus Andersen of the Norwegian Polar Institute with an anaesthetized polar bear, Svalbard, Norway.
This bear was darted from a helicopter as part of a long-term monitoring program. Every year the team spend April darting as many bears as they can and recording their weight, length and body condition. April is the best month to do this as it is the peak month for seal numbers so bears are typically in their best condition. The long-term monitoring has been running for 40 years. Such long-term studies have been critical in determining effects of climate change and pollution on polar bears.
Aerial view of Rinks Glacier on the west coast of Greenland.
This is one of a number of glaciers that has doubled or even tripled in speed in the past decade. This is in response to a dramatic increase in air temperature over Greenland of 36°F.
A swimming polar bear mother with two cubs, Svalbard, Norway.
Polar bears are technically marine mammals. They spend most of their lives on the frozen surface of the sea, where they hunt for the seals which they feed on almost exclusively. In summer, when the ice breaks up into smaller floes or melts away entirely the bears are obliged to swim to the next ice floe or to dry land. They are good swimmers and have always been known to do this. However, now the ice is breaking up earlier and re-freezing later, bears are both having to swim more and go for longer periods without feeding. This hits cubs particularly hard and scientists have found a clear link with poor sea ice cover and poor cub survival.
A submarine patrols the Arctic Ocean.
The Arctic Ocean is the shortest route between North America and Russia. Since the late 1950s, submarines from the United States, the United Kingdom and Russia have patrolled these waters. As well as looking out for enemy activity, they've also kept a record of the thickness of the ice above them — critical in case the submarine needs to surface quickly. When scientists obtained these records they discovered that the ice on the surface of the Arctic Ocean has almost halved in thickness since 1980.
The British Antarctic Survey flies over the Wilkins Ice Shelf.
A Twin Otter airplane operated by the British Antarctic Survey flies over the disintegrating Wilkins Ice Shelf on February 2010. The Wilkins Ice Shelf, a 200-meter thick sheet of floating fresh water ice larger than Jamaica, started to break up in 2008. Seven major ice shelves have broken up on the Antarctic Peninsula in the last 30 years in a wave that has been travelling southwards.
Inuit David Iqaqrialu with his dog team, Clyde River, Canada.
Sled dogs are a slower form of transportation than snowmobiles, but their fuel is a lot cheaper. They help to keep travelers safe by feeling for weak ice underfoot.