A fire burns in the exclusion zone around the Chernobyl nuclear power plant, outside the village of Rahivka, Ukraine April 5, 2020. Picture taken April 5, 2020. REUTERS/Yaroslav Yemelianenko 

Smoke rises from a forest fire in the exclusion zone around the Chernobyl nuclear power plant, outside the village of Rahivka, Ukraine April 5, 2020. Picture taken April 5, 2020. REUTERS/Yaroslav Yemelianenko 

A man views flooded properties beside the River Severn in Ironbridge, Britain, February 27, 2020. REUTERS/Toby Melville 

Foam covers the Santiago River, whose polluted waters have been linked to global manufacturers by the government of the Mexican state of Jalisco, in Juanacatlan, Mexico February 7, 2020. Picture taken February 7, 2020. REUTERS/Fernando Carranza 

A flooded street is pictured after heavy rainfall in Tiquipaya, Bolivia, February 22, 2020. REUTERS/Danilo Balderrama 

The moon shines over icebergs near Fournier Bay, Antarctica, February 3, 2020. REUTERS/Ueslei Marcelino SEARCH "ANTARCTICA PENGUINS" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

A cracked mirror leans against the rock face of a cathedral-like rock cavity after a wildfire raged through the wedding venue in Kangaroo Valley, New South Wales, Australia, January 23, 2020. REUTERS/Thomas Peter 

Melted metal from a vehicle destroyed in the recent bushfires is pictured in Conjola Park, New South Wales, Australia, January 21, 2020. REUTERS/Loren Elliott 

Algae are seen in a fishing net near Mekong river bank outside Nong Khai, Thailand January 10, 2020. REUTERS/Soe Zeya Tun 

Algae are seen in a fishing net on the Mekong river bank outside Nong Khai, Thailand January 10, 2020. REUTERS/Soe Zeya Tun 

The sun rises over dried up lake Pamamaroo, outside of Menindee, Australia, September 2, 2019. Prolonged drought exacerbated by demands on water resources by irrigators and cities means the Darling River (Barka) is running dry. The towns of Menindee and Wilcannia avoid drinking tap water, relying instead on charity donations of 10-litre boxes of water and rain tank water for potable uses. REUTERS/Tracey Nearmy SEARCH "NEARMY DROUGHT" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

A giraffe walks near the elevated railway line that allows movement of animals below the Standard Gauge Railway (SGR) line linking Nairobi and Naivasha inside the Nairobi national park in Nairobi, Kenya October 16, 2019. REUTERS/Njeri Mwangi TPX IMAGES OF THE DAY 

Giraffes walk near the elevated railway line that allows movement of animals below the Standard Gauge Railway line linking Nairobi and Naivasha inside the Nairobi national park in Nairobi, Kenya October 16, 2019. REUTERS/Njeri Mwangi 

Giraffes walk as a motorist drives near the elevated railway line that allows movement of animals below the Standard Gauge Railway (SGR) line linking Nairobi and Naivasha inside the Nairobi national park in Nairobi, Kenya October 16, 2019. REUTERS/Njeri Mwangi 

A giraffe walks near the elevated railway line that allows movement of animals below the Standard Gauge Railway (SGR) line linking Nairobi and Naivasha inside the Nairobi national park in Nairobi, Kenya October 16, 2019. REUTERS/Njeri Mwangi 

A group of impala graze near the elevated railway line that allows movement of animals below the Standard Gauge Railway (SGR) line linking Nairobi and Naivasha inside the Nairobi national park in Nairobi, Kenya October 16, 2019. REUTERS/Njeri Mwangi 

A wind-driven wildfire burns near power line tower in Sylmar, California, U.S., October 10, 2019. REUTERS/ Gene Blevins 

A wind-driven wildfire burns near power line tower in Sylmar, California, U.S., October 10, 2019. REUTERS/ Gene Blevins 

A Pillar coral (Dendrogyra cylindricus) showing a small amount of tissue loss caused by Stony Coral Tissue Loss Disease (SCTLD) stands near the University of the Virgin Islands campus in St Thomas in the U.S. Virgin Islands, May 17, 2019. REUTERS/Lucas Jackson 

A camp staff feeds Ayeyar Sein, a four-month-old baby elephant who lost her parents to poachers, after her daily wound cleaning in Wingabaw Elephant Camp, Bago, Myanmar, September 30, 2019. Picture taken September 30, 2019. REUTERS/Ann Wang TPX IMAGES OF THE DAY 

A segment of the Planpincieux glacier is seen on the Italian side of the Mont Blanc massif area of Planpincieux, Aosta, Italy, September 27, 2019. REUTERS/Yara Nardi 

A general view of the Italian side of the Mont Blanc massif area, with the Planpincieux glacier, Aosta, Italy, September 27, 2019. REUTERS/Yara Nardi 

A segment of the Planpincieux glacier is seen on the Italian side of the Mont Blanc massif area of Planpincieux, Aosta, Italy, September 27, 2019. REUTERS/Yara Nardi 

A segment of the Planpincieux glacier is seen on the Italian side of the Mont Blanc massif area of Planpincieux, Aosta, Italy, September 27, 2019. REUTERS/Yara Nardi 

A segment of the Planpincieux glacier is seen on the Italian side of the Mont Blanc massif area of Planpincieux, Aosta, Italy, September 27, 2019. REUTERS/Yara Nardi 

A segment of the Planpincieux glacier is seen on the Italian side of the Mont Blanc massif area of Planpincieux, Aosta, Italy, September 26, 2019. REUTERS/Yara Nardi 

A general view of Wildspitze summit at 3,774 meters above sea level with the Taschachferner glacier and Mittelbergferner glacier seen near the village of St. Leonhard im Pitztal, Austria, July 6, 2019. REUTERS/Lisi Niesner 

An icefall in Taschachferner glacier is seen near the village of St. Leonhard im Pitztal, Austria, July 6, 2019. REUTERS/Lisi Niesner 

A view of Gepatschferner glacier near Feichten im Kaunertal, Austria, March 21, 2019. REUTERS/Lisi Niesner 

The Jamtalferner glacier is seen near Galtuer, Austria, September 11, 2019. REUTERS/Lisi Niesner 

Meltwater from Taschachferner glacier is seen near the village of St. Leonhard im Pitztal, Austria, July 6, 2019. REUTERS/Lisi Niesner 

The summit cross of Weissseespitze at 3,500 meters above sea level is seen near Feichten im Kaunertal, Austria, March 21, 2019. REUTERS/Lisi Niesner 

The snow covered Jamtalferner glacier is seen in the morning sun near Galtuer, Austria, February 18, 2019. REUTERS/Lisi Niesner 

A view of a cross on a summit of the Goldberg group mountains as fog rises, seen from Sonnblick summit at 3,106 meters above sea level, in the Hohe Tauern mountain range near Rauris, Austria, November 23, 2018. REUTERS/Lisi Niesner 

A view of a summit in the Goldberg group mountains as fog rises, seen from Sonnblick summit at 3,106 meters above sea level, in the Hohe Tauern mountain range near Rauris, Austria, November 23, 2018. REUTERS/Lisi Niesner 

A halo, an optical phenomena from sunlight and ice crystals, rises above Goldberg group mountains, seen from Sonnblick summit at 3,106 meters above sea level, in the Hohe Tauern mountain range near Rauris, Austria, November 23, 2018. REUTERS/Lisi Niesner SEARCH "AUSTRIA GLACIERS" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

A view down at snowcapped mountains of Kaunertal valley near Feichten im Kaunertal, Austria, March 21, 2019. REUTERS/Lisi Niesner SEARCH "AUSTRIA GLACIERS" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

Icicles hang on a bog where 12,000 years ago was the Schaufelferner glacier at 2,280 meters above sea level, at Stubaier glacier ski resort near Neustift im Stubaital, Austria, October 22, 2018. REUTERS/Lisi Niesner SEARCH "AUSTRIA GLACIERS" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

A person walks next to covered depots of snow to outlast the summer in a glacier ski resort near the village of St. Leonhard im Pitztal, Austria, July 6, 2019. REUTERS/Lisi Niesner SEARCH "AUSTRIA GLACIERS" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

Ice layers are seen inside the artificial ice tunnel of Schaufelferner glacier at Stubaier glacier ski resort near Neustift im Stubaital, Austria, October 22, 2018. Glaciologist Andrea Fischer from the Austrian Institute for Interdisciplinary Mountain Research can determine weather conditions, the amount of precipitation and ice ablation of past years in these layers. REUTERS/Lisi Niesner SEARCH "AUSTRIA GLACIERS" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

A group of ski tourers make their way across the snow-covered Jamtalferner glacier near Galtuer, Austria, February 18, 2019. REUTERS/Lisi Niesner SEARCH "AUSTRIA GLACIERS" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. TPX IMAGES OF THE DAY 

Plants grow near a lake in front of Jamtalferner glacier near Galtuer, Austria, September 11, 2019. REUTERS/Lisi Niesner SEARCH "AUSTRIA GLACIERS" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

A group of scientists from the Austrian Institute for Interdisciplinary Mountain Research cross the Jamtalferner glacier near Galtuer, Austria, April 24, 2019. REUTERS/Lisi Niesner SEARCH "AUSTRIA GLACIERS" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. TPX IMAGES OF THE DAY 

The Pasterze Glacier, Austria's largest glacier, is seen below Johannisberg summit located in the Hohe Tauern mountain range, in the Austrian province of Carinthia, August 14, 2011. REUTERS/Lisi Niesner SEARCH "AUSTRIA GLACIERS" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

The Jamtalferner glacier is seen near Galtuer, Austria, April 24, 2019. REUTERS/Lisi Niesner SEARCH "AUSTRIA GLACIERS" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. TPX IMAGES OF THE DAY 

Hikers cross the Jamtalferner glacier near Galtuer, Austria, July 16, 2019. REUTERS/Lisi Niesner SEARCH "AUSTRIA GLACIERS" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

General view of the Pizol glacier, in Mels, Switzerland, September 22, 2019. REUTERS/Denis Balibouse 

People take part in a mourning ceremony as awareness to climate change, for the disappearing Pizol glacier, in Mels, Switzerland, September 22, 2019. REUTERS/Denis Balibouse 

Snow-covered mountains are seen from an atmospheric research aircraft en route to the Norwegian Sea from northern Sweden, July 30, 2019. Picture taken July 30, 2019. REUTERS/Hannah McKay 

Clouds and land are seen from an atmospheric research aircraft en route to the Norwegian Sea from northern Sweden, July 30, 2019. Picture taken July 30, 2019. REUTERS/Hannah McKay 

A burning tree is seen during a fire in an area of the Amazon rainforest in Itapua do Oeste, Rondonia State, Brazil, September 11, 2019. Picture taken September 11, 2019. REUTERS/Bruno Kelly TPX IMAGES OF THE DAY 

A burning tree is seen during a fire in an area of the Amazon rainforest in Itapua do Oeste, Rondonia State, Brazil, September 11, 2019. Picture taken September 11, 2019. REUTERS/Bruno Kelly 

The Wahlenberg Glacier is seen in Oscar II land at Spitsbergen in Svalbard, Norway, August 5, 2019. REUTERS/Hannah McKay 

The Wahlenberg Glacier is seen in Oscar II land at Spitsbergen in Svalbard, Norway, August 5, 2019. REUTERS/Hannah McKay 

The Wahlenberg Glacier is seen in Oscar II land at Spitsbergen in Svalbard, Norway, August 5, 2019. REUTERS/Hannah McKay 

The Wahlenberg Glacier is seen in Oscar II land at Spitsbergen in Svalbard, Norway, August 5, 2019. REUTERS/Hannah McKay 

The Villarrica Volcano is seen at night from Pucon town, Chile, September 11, 2019. REUTERS/Cristobal Saavedra Escobar 

A fire burns a tract of Amazon jungle near Porto Velho, Brazil September 9, 2019. Picture taken September 9, 2019. REUTERS/Bruno Kelly 

The Dom des Mischabel mountain is pictured from Belalp, Switzerland, September 4, 2019. Picture taken September 4, 2019. REUTERS/Denis Balibouse 

The Fletschhorn mountain is pictured from Belalp, Switzerland, September 4, 2019. Picture taken September 4, 2019. REUTERS/Denis Balibouse