Ice forms on a house during blizzard in Hamburg, New York, U.S., February 28, 2020. REUTERS/Lindsay DeDario 

Ice forms on a house during a blizzard in Hamburg, New York, U.S., February 28, 2020. REUTERS/Lindsay DeDario TPX IMAGES OF THE DAY 

A view shows a giant foot print, which was trodden on the ground following an early snowfall in the Siberian city of Omsk, Russia October 18, 2019. REUTERS/Alexey Malgavko TPX IMAGES OF THE DAY 

A paraglider flies above the Bossons glacier in the Mont-Blanc massif on a sunny autumn day in Chamonix, France October 8, 2019. REUTERS/Denis Balibouse 

The Bossons glacier in the Mont-Blanc massif is pictured on a sunny autumn day in Chamonix, France October 8, 2019. REUTERS/Denis Balibouse 

Snow is protected with fabric to prevent it from melting on a ski slope in a glacier ski resort near the village of St. Leonhard im Pitztal, Austria, July 6, 2019. REUTERS/Lisi Niesner 

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 

Two fishermen stand in front of the Italian side of the Mont Blanc massif area of Planpincieux, Aosta, Italy, September 26, 2019. REUTERS/Yara Nardi 

General view of a closed Val Ferret road on the Italian side of the Mont Blanc massif area of Planpincieux, Aosta, Italy, September 26, 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 

General view of a closed Val Ferret road on the Italian side of the Mont Blanc massif area of Planpincieux, Aosta, Italy, September 26, 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 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 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 the Italian side of the Mont Blanc massif area, with the Planpincieux glacier, Aosta, Italy, September 26, 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 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. 

The Wildsee lake is pictured in the Swiss Alps above Bad Ragaz in Mels, Switzerland, September 22, 2019. Picture taken September 22, 2019. REUTERS/Denis Balibouse 

The Mont-Blanc is pictured from Les Diablerets, Switzerland, September 13, 2019. Picture taken September 13, 2019. REUTERS/Denis Balibouse 

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 

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 

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 

A boy uses his oar to break ice to move his boat on the frozen Anchar Lake on a cold winter day in Srinagar December 27, 2018. REUTERS/Danish Ismail 

A view shows the Siberian city of Krasnoyarsk on a foggy frosty day, with the air temperature at about minus 29 degrees Celsius (minus 20.2 degrees Fahrenheit), Russia December 26, 2018. REUTERS/Ilya Naymushin 

A view shows the Paraskeva Pyatnitsa Chapel, the city's oldest building, with the air temperature at about minus 29 degrees Celsius (minus 20.2 degrees Fahrenheit), on a foggy frosty day in the Siberian city of Krasnoyarsk, Russia December 26, 2018. REUTERS/Ilya Naymushin 

A Siberian taiga forest at the banks of Yenisei river, covered with a frosty evaporation with the air temperature at about -31 degrees Celsius during sunset, is seen outside Krasnoyarsk, Russia December 24, 2018. REUTERS/Ilya Naymushin 

A Siberian taiga forest at the banks of Yenisei river, covered with a frosty evaporation with the air temperature at about -31 degrees Celsius during sunset, is seen outside Krasnoyarsk, Russia December 24, 2018. REUTERS/Ilya Naymushin 

A bridge across the Yenisei river is seen during sunset with the air temperature at about -31 degrees Celsius outside Krasnoyarsk, Russia December 24, 2018. REUTERS/Ilya Naymushin