David Noton / Dramatic evening sky over Anse Source d'Argent, La Digue. Seychelles. February 2007.

Juan Carlos Munoz / Aerial image showing light reflected off the deep blue of the sea around the Bahamas archipelago, Caribbean, February 2012

Orsolya Haarberg / Rain clouds over Blonduhli­darfjoll, Iceland, January 2011

Roy Mangersnes / Arctic fox (Alopex / Vulpes lagopus) standing, near Longyearbyen, Spitsbergen, Svalbard, Norway, August

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

Mark Hamblin / 2020VISION / Windswept Silver birch trees (Betula pendula) silhouetted against sky, Cairngorms National Park, Scotland, UK, November. Did you know? Silver birch trees can produce millions of tiny seeds every year.

Ole Jorgen Liodden / Thunderstorm and bushfire at night. Kalahari, Botswana, November.

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

David Tipling / 2020VISION / Pink-footed geese (Anser brachyrynchus) flocks in flight leaving overnight roost at dawn, the Wash, Snettisham, Norfolk, UK, January

Stefan Huwiler / Matterhorn at sunrise in autumn with reflection in the Riffelsee. Zermatt, Valais, Switzerland, Europe, October 2008.

Pascal Tordeux / Lone Walnut (Juglans) tree in a field of barley. Picardy, France.

Niall Benvie / 2020VISION / Silhouette of Stac Pollaidh against storm sky, viewed from Tanera More, Coigach and Assynt, Sutherland, Scotland, UK, July 2011

Diane McAllister / The snow at Horsetail Falls' begins to melt in mid-February, enabling the falls to resume once again. The clear sky and low sun angle ignite the rock wall during sundown. Yosemite National Park, Calif...

Inaki Relanzon / Dramatic light on Benijo Beach. Anaga Peninsula, Tenerife, Canary Islands, February 2011.

Juergen Freund / Lightning storm over the Australian outback at dusk. Queensland, Australia, February 2008

Inaki Relanzon / Volcanic eruption, Eyjafjallajokull, near the Myrdalsjokull glacier, South Iceland, april 2010.

Pete Oxford / Brown-chested martins (Progne tapera) roosting on telegraph wires, Puerto Lopez, Santa Elena Peninsula, Manabi Province, Ecuador

Bernard Castelein / Reflection of mountain range, in Tso Kar lake, Ladakh, India, June 2010

Bernard Castelein / Spituk Gompa seen from the left bank of the Indus river, Leh region, Ladakh, India, June 2010

Floris van Breugel / Sensationally twisted sandstone curves of Arizona's famous wave formation seen under partly cloudy skies. Vermilion Cliffs, Arizona, USA, December 2007.

Floris van Breugel / Reflections of winter trees in water, under classically grey winter skies, Oisterwijk, Netherlands, Europe. December 2006.

Floris van Breugel / Ancient Bristlecone Pine tree (Pinus longaeva) at sunset. White Mountains, California, USA, June 2009

Philip Stephen / Fishing vessel "Harvester" heading to North Sea fishing grounds in stormy weather. Europe, November 2010. Property released.

Jack Dykinga / Eroded formation known as the 'Tres Maries', in the Valle de la Luna. One million year old composition of gravel, clay, salt, gems and quartz, against The Milky Way and Southern Cross in the night sky...

Jack Dykinga / Eroded rock formation known as the 'Tres Maries', in the Valle de la Luna. One million year old composition of gravel, clay, salt, gems and quartz, against The Milky Way and Southern Cross in the nigh...

Steve Knell / Boreray, under low cloud cover. This holds the largest gannetry in UK (60,000 pairs) St. Kilda, Scotland, July 2009

Inaki Relanzon / Lighthouse on Snafellsness Peninsula, Iceland, July 2008

Nick Garbutt / Flock of Kelp / Southern black backed Gulls (Larus dominicanus) flying over iceberg. Graham Passage, Antarctic Peninsula, Antarctica. February. (digitally altered image)

David Noton / Morraine Lake, in the Valley of the Ten Peaks, after recent snowfall, Banff National Park, Alberta, Canada. October 2009

Jeff Wilson / Markhor (Capra falconeri) male silhouetted in the Hindu Kush mountains, North West frontier, Pakistan, photographed whilst on location filming for BBC Planet Earth series, 2005

Jeff Wilson / Aerial view of glaciated valley of Concordia, Karakoram Mountains, Himalayas, Pakistan. From Pakistani military helicopter for BBC series Planet Earth April 2005

Jeff Wilson / Aerial view of K2 and glaciated valley of Concordia, Karakoram Mountains, Himalayas, Pakistan. From Pakistani military helicopter for BBC series Planet Earth April 2005

Jeff Wilson / Aerial view of K2 and glaciated valley, Concordia, Karakoram Mountains, Himalayas, Pakistan. From Pakistani military helicopter for BBC series Planet Earth 2005

Aflo / Y-10805 Forked lightning racing across sky at night

Neil Lucas / Dragons blood tree (Dracena cinnibaris) reflected, Socotra, Yemen, February 2007. Digitally created image

Steven Kazlowski / Glacial landscape in Smeerenburgfjorden, along the northwest coast of Svalbard, Norway, Europe. July 2009

Steven Kazlowski / Inupiaq / Inuit man hold his hand under the midnight sun in the Chukchi Sea, off shore from the arctic village of Barrow, Alaska, USA. April 2009

Uri Golman / Sunset over iceberg. Jakobshavn, Ilulissat, Kangia, Icefjord, Greenland. August 2006.

Alex Hyde / Derwent Edge after rainstorm, with gritstone boulders in foreground. Peak District National Park, England. March 2008.

Andy Rouse / Aerial view of ice ridges at front of Peters Glacier, King Haakon Bay, South Georgia, Antarctica, December 2006

Andy Rouse / Aerial view of Warburton Peak, South Georgia, Antarctica, December 2006

Jack Dykinga / Rio Grande passing through the towering cliffs of the Mariscal Canyon, Texas, USA

Jeff Vanuga / Lone Star Geyser erupting in Lone Star Geysyer Basin at night, Yellowstone National Park, Wyoming, USA, October 2007

Michael Hutchinson / Perito Moreno Glacier, Los Glaciares National Park, Argentina February 2009

Paul Hobson / Large flocks of Common starlings (Sturnus vulgaris) going to roost at dusk, Gretna Green, Scotland

Jack Dykinga / Sunset at Yaki Point on the South Rim with stratified rim rocks and minute storm clouds inside the canyon below, Grand Canyon National Park, Arizona, USA.

Staffan Widstrand / Coastline with iceberg, Antarctic Peninsula

David Curl / Lightning over Ayers Rock, Uluru NP, Northern Territory, Australia, desert

Pete Oxford / African Elephants & mixed game at waterhole {Loxodonta africana} Chobe NP, Botswana

LYNN M. STONE / Bald eagle in flight against blue sky, Alaska

GRANT MCDOWELL / Dust storm preceeding thunderstorm in the Sahel, Mali NB Person watching

Anup Shah / Rainstorm approaching on Masai Mara, Kenya - Clouds, dramatic sky, rain storm, trees

Doug Allan / Ice cliffs of the Ross ice shelf, Antarctica

David Noton / The Old Man of Storr in dramatic light, Trotternish Isle of Skye, Scotland

Marie Read / Single-leaf pinyon pine (Pinus monophylla) trees, with dramatic clouds in late summer Mono Lake Basin, California, USA, July.

Peter Cairns / Summer pack ice and dramatic sky, Svalbard, Norway

Peter Cairns / Mountain ridge and dramatic sky, Svalbard, Norway

Rolf Nussbaumer / Trecul yucca / Spanish dagger (Yucca treculeana) at night, Dinero, Lake Corpus Christi, South Texas, USA.

Mark Hamblin / 2020VISION / Windswept Silver birch trees (Betula pendula) silhouetted against sky, Cairngorms National Park, Scotland, UK, November

Peter Cairns / 2020VISION / Dramatic skies off Neist Point, Isle of Skye, Inner Hebrides, Scotland, UK, June 2011

Peter Cairns / Dramatic light over sea at dusk, Hermaness NNR, Shetland Islands, Scotland, UK, June 2010

Ernie Janes / Tractor ploughing in large arable field, Baldock, Hertfordshire, UK

Peter Cairns / 2020VISION / Stormy light over Traigh Losgaintir, North Harris, Western Isles / Outer Hebrides, Scotland, UK, May 2011

Peter Cairns / 2020VISION / Stormy light over Traigh Losgaintir, North Harris, Western Isles / Outer Hebrides, Scotland, UK, May 2011

Niall Benvie / 2020VISION / Clouds in sky over the uplands, Coigach and Assynt, Sutherland, Scotland, UK, June 2011

Niall Benvie / 2020VISION / Dramatic sky at sunset, looking in the direction of Reiff from Old Dornie, Achiltibuie, Coigach and Assynt, Sutherland, Scotland, UK, June 2011. Did you know? Achiltibuie is part of Scotland's first G...

Niall Benvie / 2020VISION / Dramatic sky at sunset, Coigach and Assynt, Sutherland, Scotland, UK, June 2011

Niall Benvie / 2020VISION / Rainbow over Stac Pollaidh, Coigach and Assynt, Sutherland, Scotland, UK, June 2011

Niall Benvie / 2020VISION / Clouds over Stac Pollaidh, Coigach and Assynt, Sutherland, Scotland, UK, June 2011

Niall Benvie / 2020VISION / Cloud formations in sky above silhouette of Stac Pollaidh viewed from Tanera More, Coigach and Assynt, Sutherland, Scotland, UK, July 2011

Niall Benvie / 2020VISION / Silhouette of Stac Pollaidh against sotrm sky, viewed from Tanera More, Coigach and Assynt, Sutherland, Scotland, UK, July 2011

Ernie Janes / Person walking dog along Holkham Beach at sunset, winter, North Norfolk

Bryan and Cherry Alexander / Gentoo penguins (Pygoscelis papua) in blowing sand under a dramatic sky on Saunders Island, Falkland Islands, 2009

Ernie Janes / Stubble field and round straw bales after harvest, Norfolk, UK, August

Peter Cairns / 2020VISION / Stormy sky off Arisaig looking to small isles, NW Highlands, Scotland, UK, may 2010

Peter Cairns / 2020VISION / Stormy sky off Arisaig looking to small isles, NW Highlands, Scotland, UK, May 2010

Peter Cairns / 2020VISION / Stormy sky off Arisaig looking to small isles, NW Highlands, Scotland, UK, May 2010

Inaki Relanzon / Limestone formations against a dusky sky. Torcal de Antequera Nature Reserve, Malaga, Spain, November 2009.

Matthew Maran / Rough seas crashing against rocky shore in front of a dramatic cloudy sky. The Broken Group Islands, Ucluelet, Vancouver Island, Canada.

Peter Cairns / 2020VISION / Dramatic light over sea at dusk, Hermaness NNR, Unst, Shetland Islands, Scotland, UK, June 2010.

Peter Cairns / 2020VISION / Silhouette of photographer Mark Hamblin against dramatic light over sea at dusk, Hermaness NNR, Unst, Shetland Islands, Scotland, UK, June 2010. Model released.

Peter Cairns / 2020VISION / Dramatic light over sea at dusk, Hermaness NNR, Shetland Isles, Scotland, UK, June 2010

Nick Upton / Sun rising over flooded Biebrza marshes, with a single Mute swan (Cygnus olor) swimming near reed beds, Biebrza National Park, Podlaskie, Poland, April.

Peter Cairns / Dramatic light over sea at dusk. Hermaness NNR, Shetland, Scotland, June.

Eric Baccega / Sunset on Baffin Island, with mountain silhouetted against sky, Nunavut, Canada, August 2010

Gerrit Vyn / Sagebrush (Asteraceae) in winter landscape, with tiny remnants of snow, Freemont County, Wyoming, USA, March 2010.

Graham Eaton / Dramatic sunset at Helsby Hill, Cheshire, December 2009

Graham Eaton / Snow-bearing clouds approaching the coast, viewed from the old coastguard station, Aberdaron, Gwynedd, Wales, January 2010

Ross Hoddinott / Portland Bill lighthouse, long exposure, Portland, near Weymouth, Dorset, England, UK. February 2010.

David Noton / The Valley of the Ten Peaks, after recent snowfall, Banff National Park, Alberta, Canada. October 2009

Jeff Wilson / Aerial view of Concordia confluence, Karakoram Mountains, Pakistan, from Pakistani military helicopters for BBC series Planet Earth, April 2005

Nick Upton / Stormy sky over Hiddensee island with flashing lighthouse and Baltic sea at sunset. Viewed from Rugen island, Mecklenberg-Vorpommern, Germany.

Nick Upton / Blue sky and cumulo nimbus storm clouds building at dawn. Mecklenberg-Vorpommern, Germany.