Ingo Arndt / Perito Moreno glacier, calving sequence 3/3 Patagonia, Argentina

Ingo Arndt / Perito Moreno glacier, calving sequence 2/3 Patagonia, Argentina

Orsolya Haarberg / Glacier ice floating in the Jokulsarlon glacier lagoon, with Fjallsjokull in the background, sunrise, Iceland, September 2010

Jack Dykinga / Moreno Glacier calving iceberg in Glaciers National Park, Argentina

Ralph Pace / Tourists and calving glacier, South Sawyer Glacier, Alaska

Ingo Arndt / Ice calving from terminal moraine, Perito Moreno Glacier, Los Glaciares National Park, Patagonia, Argentina

Ashley Cooper / Jokulsarlon ice lagoon, Iceland. September 2010.

Ashley Cooper / Arched Iceberg collapsing into the sea, calved from the Jacobshavn glacier or Sermeq Kujalleq, Greenland, July 2008.

Ashley Cooper / Arched Iceberg collapsing into the sea, calved from the Jacobshavn glacier or Sermeq Kujalleq, Greenland, July 2008.

Ashley Cooper / Small collapse of ice from the Russells Glacier, Kangerlussuaq, Greenland. July 2008.

Ashley Cooper / Collasing ice from the Russells Glacier, Kangerlussuaq, Greenland. July 2008.

Ashley Cooper / The Russells Glacier, Kangerlussuaq, Greenland. July 2008.

Ashley Cooper / The Russells Glacier and pool of meltwater at terminus, Kangerlussuaq, Greenland, July.

Ashley Cooper / Melt water from the Russells Glacier, Greenland, July 2008.

Ashley Cooper / The Eqip sermia glacier that is receeding rapidly due to global warming on the west coast of Greenland.

Ashley Cooper / The Eqip sermia glacier that is receeding rapidly due to global warming on the west coast of Greenland.

Ashley Cooper / Eqip Sermia on the west Greenland coast, showing the lateral moraine on the side of the glacier where it has receeded due to global warming. Greenland, July 2008.

Ashley Cooper / Russells Glacier with calved ice and meltwater, Greenland, July 2008.

Peter Mather / Caribou (Rangifer tarandus) newborn calf nuzzling mother, of the porcupine herd, Arctic National Wildlife Refuge, Alaska

Peter Mather / Caribou (Rangifer tarandus) mother and newborn calf, of the porcupine herd, Arctic National Wildlife Refuge, Alaska

Yva Momatiuk & John Eastcott / Ice calving off glacier, Lake Argentino, Los Glaciares National Park, Patagonia, Argentina

Jaymi Heimbuch / Large piece of ice calving off Johns Hopkins Glacier, Glacier Bay National Park, Alaska

Pal Hermansen / Glacier calving, Kongsfjorden,Svalbard, Norway, July 2016.

Gabriel Rojo / Ice calving from Perito Moreno Glacier, Los Glaciares National Park, Santa Cruz, Patagonia, Argentina. February 2010.

Gabriel Rojo / Ice calving from Perito Moreno Glacier, Los Glaciares National Park, Santa Cruz, Patagonia, Argentina. February 2010.

Gabriel Rojo / Ice calving from Perito Moreno Glacier, Los Glaciares National Park, Santa Cruz, Patagonia, Argentina. February 2010.

Wim van den Heever / A glacier calving into the ocean, Svalbard, Norway, July 2013

Roy Mangersnes / Glacier calving causing kittiwakes (Rissa tridactyla) to take to the air in panic, west coast of Svalbard, Norway, August.

Jack Dykinga / Grey Glacier tumbling into Lago Grey, calving blue-green icebergs into the lake, Torres del Paine National Park, Chile. April 2014.

Jack Dykinga / Grey Glacier tumbling into Lago Grey, calving blue-green icebergs into the lake, Torres del Paine National Park, Chile. April 2014.

Hiroya Minakuchi / Ice falling off glacier, Alaska

Enrique Lopez-Tapia / Ice calving from the Perito Moreno glacier, Los Glaciares National Park, Patagonia, Argentina, October 2006.

Hiroya Minakuchi / Calving glacier, Alaska

Hiroya Minakuchi / Glacier calving, Alaska

Matthias Breiter / Glacial ice calving into the water, Sawyer Glacier, Tracy Arm Fjord, Alaska

Yva Momatiuk & John Eastcott / Melting ice from calving glaciers left on beach by high tide in spring, St. Andrews Bay, South Georgia Island

Yva Momatiuk & John Eastcott / Melting ice from calving glaciers left on beach by high tide in spring, St. Andrews Bay, South Georgia Island

Yva Momatiuk & John Eastcott / Melting ice from calving glaciers left on beach by high tide in spring, St. Andrews Bay, South Georgia Island

Yva Momatiuk & John Eastcott / Melting ice from calving glaciers left on beach by high tide in spring, St. Andrews Bay, South Georgia Island

Konrad Wothe / Dawes Glacier calving, Endicott Arm, Inside Passage, Alaska

Michio Hoshino / Caribou (Rangifer tarandus) calf from Porcupine herd at calving grounds, ANWR, Alaska

Yva Momatiuk & John Eastcott / Twitcher Glacier beneath mountains of Salversen Range with bergy bits melted from calving chunks of ice, South Georgia Island, Southern Ocean, Antarctic Convergence

Colin Monteath / Pack ice and calving icebergs, aerial view of Mertz Glacier, Terre Adelie Land, east Antarctica

Hanne & Jens Eriksen / San Rafael Glacier calving, Chilean Fjords, Chile, South America

Michio Hoshino / Hubbard Glacier calving, Alaska

Michio Hoshino / Hubbard Glacier calving, Alaska

Michio Hoshino / Caribou (Rangifer tarandus) aerial view of Porcupine Herd at calving ground on coastal plain, Arctic National Wildlife Refuge, Alaska

Michio Hoshino / Caribou (Rangifer tarandus) of the Porcupine Herd at calving grounds on coastal plain, Arctic National Wildlife Refuge, Alaska

Michio Hoshino / Caribou (Rangifer tarandus) aerial view of Porcupine Herd at calving ground on coastal plain, Arctic National Wildlife Refuge, Alaska

Michio Hoshino / Caribou (Rangifer tarandus) of the Porcupine Herd on tundra calving grounds, Arctic National Wildlife Refuge, Alaska

Tui De Roy / Perito Moreno Glacier being cut back by water pressure from trapped Lake Argentina, Los Glaciares National Park, Patagonia, Argentina

Tui De Roy / Perito Moreno Glacier being cut back by water pressure from trapped Lake Argentina, Los Glaciares National Park, Patagonia, Argentina

Tui De Roy / Perito Moreno Glacier being cut back by water pressure from trapped Lake Argentina, Los Glaciares National Park, Patagonia, Argentina

Tui De Roy / Perito Moreno Glacier actively advancing into Lake Argentina, Los Glaciares National Park, Argentina

Flip Nicklin / Gray Whale (Eschrichtius robustus) spyhopping in calving lagoon, Baja California, Mexico

Pete Oxford / Perito Moreno glacier calving sequence 1 of 4, Los Glaciares NP, Argentina, South America

Pete Oxford / Perito Moreno glacier calving sequene 2 of 4, Los Glaciares NP, Argentina, South America

Pete Oxford / Perito Moreno glacier calving sequence 3 of 4, Los Glaciares NP, Argentina, South America

Pete Oxford / Perito Moreno glacier calving sequence 4 of 4, Los Glaciares NP, Argentina, South America

Flip Nicklin / Humpback Whale (Megaptera novaeangliae) curious calf near end of calving season, Maui, Hawaii

Peter Mather / Caribou (Rangifer tarandus) mother and newborn calf, of the porcupine herd, Arctic National Wildlife Refuge, Alaska

Peter Mather / Caribou (Rangifer tarandus) bull and females, of the porcupine herd, at calving grounds in fog, Arctic National Wildlife Refuge, Alaska

Peter Mather / Caribou (Rangifer tarandus) mother grazing with calf, of the porcupine herd, grazing, Arctic National Wildlife Refuge, Alaska

Peter Mather / Caribou (Rangifer tarandus) mother licking newborn calf, of the porcupine herd, Arctic National Wildlife Refuge, Alaska

Peter Mather / Caribou (Rangifer tarandus) mother and newborn calf, of the porcupine herd, Arctic National Wildlife Refuge, Alaska

Peter Mather / Caribou (Rangifer tarandus) newborn calf, of the porcupine herd, sleeping, Arctic National Wildlife Refuge, Alaska

Flip Nicklin / Tourists watching calving glacier, Alaska

Yva Momatiuk & John Eastcott / Ice calving off glacier, Lake Argentino, Los Glaciares National Park, Patagonia, Argentina, sequence 4 of 4

Yva Momatiuk & John Eastcott / Ice calving off glacier, Lake Argentino, Los Glaciares National Park, Patagonia, Argentina, sequence 3 of 4

Yva Momatiuk & John Eastcott / Ice calving off glacier, Lake Argentino, Los Glaciares National Park, Patagonia, Argentina, sequence 2 of 4

Yva Momatiuk & John Eastcott / Ice calving off glacier, Lake Argentino, Los Glaciares National Park, Patagonia, Argentina, sequence 1 of 4

Yva Momatiuk & John Eastcott / Ice calving off glacier, Lake Argentino, Los Glaciares National Park, Patagonia, Argentina

Jaymi Heimbuch / Large piece of ice calving off Johns Hopkins Glacier, Glacier Bay National Park, Alaska

Peter Mather / Coastal plain, which is the calving and nursing grounds of Porcupine caribou herd and is threatened by potential oil and gas development, Arctic National Wildlife Refuge, Alaska

Peter Mather / Aerial of coastal plain, which is the calving and nursing grounds of Porcupine caribou herd and is threatened by potential oil and gas development, Arctic National Wildlife Refuge, Alaska

Hiroya Minakuchi / Ice falling off glacier, Alaska

Michio Hoshino / Caribou (Rangifer tarandus) aerial view of Porcupine Herd migrating across tundra to calving grounds, Arctic National Wildlife Refuge, Alaska

Michio Hoshino / Caribou (Rangifer tarandus) aerial view of calving grounds of the Porcupine Herd on coastal plain near western slope of Brooks Range, Arctic National Wildlife Refuge, Alaska

Charlie Hamilton-James / Blue wildebeest (Connochaetes taurinus) and Zebra (Equus quagga) herds moving towards Ndutu lake in the evening during the February calving event, Serengeti National Park, Tanzania, Africa.

Charlie Hamilton-James / Blue wildebeest (Connochaetes taurinus) and Zebra (Equus quagga) herds moving towards Ndutu lake in the evening during the February calving event, Serengeti National Park, Tanzania, Africa.

Charlie Hamilton-James / Blue wildebeest (Connochaetes taurinus) and Zebra (Equus quagga) herds moving towards Ndutu lake in the evening during the February calving event, Serengeti National Park, Tanzania, Africa.

Charlie Hamilton-James / Blue wildebeest (Connochaetes taurinus) herd moving towards Ndutu lake in the evening during the February calving event, Serengeti National Park, Tanzania, Africa.

Michel Roggo / Aerial view of the front of the Sermeq Kujalleq Glacier, Greenland, entering the Kangia Ilulissat Icefjord full of icebergs. The icebergs are produced by the Sermeq Kujalleq Glacier, one of the fastes...

Espen Bergersen / Lilliehook glacier, calving sequence 2/2. Spitsbergen, Svalbard, Norway. 25th July 2020.

Espen Bergersen / Lilliehook glacier, calving sequence 1/2. Spitsbergen, Svalbard, Norway. 25th July 2020.

Erlend Haarberg / Reindeer herders on snowmobiles, moving a large flock of semi-domesticated Reindeer (Rangifer tarandus), to the reindeer calving areas in the Jotunheimen National Park, Norway. April.

Orsolya Haarberg / Aerial view of reindeer herders on snowmobiles, moving a large flock of semi-domesticated Reindeer (Rangifer tarandus), to the reindeer calving areas in the Jotunheimen National Park, Norway. April.

Orsolya Haarberg / Aerial view of reindeer herders moving a large herd of semi-domesticated Reindeer (Rangifer tarandus) with the help of snowmobiles, to the reindeer calving areas in the Jotunheimen National Park, Norw...

Orsolya Haarberg / Reindeer herders moving a large herd of semi-domesticated Reindeer (Rangifer tarandus) with the help of snowmobiles, to the reindeer calving areas in the Jotunheimen National Park, Norway. April.

Orsolya Haarberg / Reindeer herders moving a large flock of semi-domesticated Reindeer, (Rangifer tarandus), with the help of snowmobiles, to the calving areas in the Jotunheimen National Park, Norway. Here, the flock i...

Orsolya Haarberg / Reindeer herders moving a large flock of semi-domesticated Reindeer (Rangifer tarandus), with the help of snowmobiles, to the reindeer calving areas in the Jotunheimen National Park, Norway. Here, the...

Erlend Haarberg / Reindeer herders moving a large flock of semi-domesticated Reindeer (Rangifer tarandus), with the help of snowmobiles, to the reindeer calving areas in the Jotunheimen National Park, Norway. April 202...

Erlend Haarberg / Reindeer herders moving a large flock of semi-domesticated Reindeer (Rangifer tarandus), with the help of snowmobiles, to the reindeer calving areas in the Jotunheimen National Park, Norway. April 202...

Erlend Haarberg / Reindeer herders moving a large flock of semi-domesticated Reindeer (Rangifer tarandus) with the help of snowmobiles, to the reindeer calving areas in the Jotunheimen National Park, Norway. Mt Semmelh...

Frederique Olivier / Handheld shot of a glacier terminus, about to calve, with a large flock of Kittiwakes (Rissa tridactyla), Svalbard, 2016.

Frederique Olivier / Tracking shot showing remnants of a large glacial calving event, with glacier in the background, Greenland, 2016.