Bryan and Cherry Alexander / Aerial view of the south of Oscar II Land seen from above the Isfjorden. Prins Karls Forland behind. Spitsbergen, Svalbard, Norway, June 2008.

Bryan and Cherry Alexander / Receding ice cap and glaciers on the coast of Northwest Greenland, September 2008.

Bryan and Cherry Alexander / The Amundsen-Scott Research Station on the Polar Plateau. South Pole, Antarctica, January 2006.

Bryan and Cherry Alexander / Aerial view of the Amundsen-Scott Research Station, South Pole, Antarctica, January 2006.

Bryan and Cherry Alexander / Gas drilling platform on the tundra in Gazprom's Bovanenkovo field. Yamal, Western Siberia, Russia, 1993.

Bryan and Cherry Alexander / Aerial view of Greenland Icecap from near Cape York. Northwest Greenland, 1991

Bryan and Cherry Alexander / Aerial view of Greenland Icecap from near Cape York. Northwest Greenland, 1991.

Bryan and Cherry Alexander / Aerial view of Greenland Icecap from near Cape York. Northwest Greenland, 1991.

Bryan and Cherry Alexander / Aerial view of Meteorite Bay showing icebergs frozen into new sea ice. Northwest Greenland, 1996.

Bryan and Cherry Alexander / Golfball radars, part of the US missile defence system near Thule Airbase in Northwest Greenland, 1996. Editorial use only.

Bryan and Cherry Alexander / Fish eye photograph of the Polar Pack Ice, with ice floes, leads and meltpools. Arctic Ocean, 1998.

Bryan and Cherry Alexander / Aerial view of lake freezing in Autumn surrounded by snow covered boreal forest. Labrador, Canada, 1997.

Juergen Freund / Aerial view of broken ice fields, St Lawrence stream, Magdalen Islands, Canadian Arctic

Juergen Freund / Looking down onto broken ice fields, St Lawrence stream, Magdalen Islands, Canada