People visit Santa Claus Office located on the Arctic Circle near Rovaniemi, Finland December 13, 2019. Picture taken December 13, 2019. REUTERS/Attila Cser

A man dressed as Santa Claus poses for a picture near Santa Claus Office located on the Arctic Circle near Rovaniemi, Finland December 13, 2019. Picture taken December 13, 2019. REUTERS/Attila Cser

People visit Santa Claus Office located on the Arctic Circle near Rovaniemi, Finland December 13, 2019. Picture taken December 13, 2019. REUTERS/Attila Cser

The nuclear-powered icebreaker Arktika is seen drawn by tug boats as it starts the sea trials, in Saint Petersburg, Russia December 12, 2019. REUTERS/Anton Vaganov

The nuclear-powered icebreaker Arktika is seen drawn by tug boats as it starts the sea trials, in Saint Petersburg, Russia December 12, 2019. REUTERS/Anton Vaganov

Helen Julian, a volunteer from the Old Weather group, poses for a photograph at her laptop in Darlington, Britain, December 6, 2019. A group of far-flung volunteers called Old Weather is painstakingly extracting data from the handwritten logbooks of 19th-century ships to help us understand how the Earth's climate is changing. Founded a decade ago, Old Weather's volunteers have accumulated an astonishing 4 million observations of weather and ice, taken mostly from the logbooks of ships plying northern or Arctic routes. Picture taken December 6, 2019. To match Special Report CLIMATE-CHANGE/ICE-SHIPLOGS. REUTERS/Lee Smith

Dr. Kevin Wood, a research scientist at the NOAA Pacific Marine Environmental Laboratory – University of Washington Joint Institute for the Study of the Atmosphere and Ocean, stands for a portrait at the NOAA campus in Seattle, Washington, U.S., December 6, 2019. Wood is the lead investigator on the Old Weather Arctic project, which uses volunteer-collected historical weather data from thousands of pages of ships' logs to help inform climate projections. Picture taken December 6, 2019. To match Special Report CLIMATE-CHANGE/ICE-SHIPLOGS REUTERS/Lindsey Wasson

Old Weather volunteer Joan Arthur poses for a photograph at her home in Oxford, Britain, November 25, 2019. A group of far-flung volunteers called Old Weather is painstakingly extracting data from the handwritten logbooks of 19th-century ships to help us understand how the Earth's climate is changing. Founded a decade ago, Old Weather's volunteers have accumulated an astonishing 4 million observations of weather and ice, taken mostly from the logbooks of ships plying northern or Arctic routes. Picture taken November 25, 2019. To match Special Report CLIMATE-CHANGE/ICE-SHIPLOGS REUTERS/Eddie Keogh

Dr. Kevin Wood, a research scientist at the NOAA Pacific Marine Environmental Laboratory – University of Washington Joint Institute for the Study of the Atmosphere and Ocean, stands for a portrait at the NOAA campus in Seattle, Washington, December 6, 2019. Wood is the lead investigator on the Old Weather Arctic project, which uses volunteer-collected historical weather data from thousands of pages of ships' logs to help inform climate projections. Picture taken December 6, 2019. To match Special Report CLIMATE-CHANGE/ICE-SHIPLOGS REUTERS/Lindsey Wasson

Helen Julian, a volunteer from the Old Weather group, poses for a photograph in Darlington, Britain, December 6, 2019. A group of far-flung volunteers called Old Weather is painstakingly extracting data from the handwritten logbooks of 19th-century ships to help us understand how the Earth's climate is changing. Founded a decade ago, Old Weather's volunteers have accumulated an astonishing 4 million observations of weather and ice, taken mostly from the logbooks of ships plying northern or Arctic routes. Picture taken December 6, 2019. To match Special Report CLIMATE-CHANGE/ICE-SHIPLOGS. REUTERS/Lee Smith

Helen Julian, a volunteer from the Old Weather group, poses for a photograph in Darlington, Britain, December 6, 2019. A group of far-flung volunteers called Old Weather is painstakingly extracting data from the handwritten logbooks of 19th-century ships to help us understand how the Earth's climate is changing. Founded a decade ago, Old Weather's volunteers have accumulated an astonishing 4 million observations of weather and ice, taken mostly from the logbooks of ships plying northern or Arctic routes. Picture taken December 6, 2019. To match Special Report CLIMATE-CHANGE/ICE-SHIPLOGS. REUTERS/Lee Smith

Dr. Kevin Wood, a research scientist at the NOAA Pacific Marine Environmental Laboratory – University of Washington Joint Institute for the Study of the Atmosphere and Ocean, sits for a portrait at the NOAA campus in Seattle, Washington, U.S., December 6, 2019. Wood is the lead investigator on the Old Weather Arctic project, which uses volunteer-collected historical weather data from thousands of pages of ships' logs to help inform climate projections. Picture taken December 6, 2019. To match Special Report CLIMATE-CHANGE/ICE-SHIPLOGS REUTERS/Lindsey Wasson

Dr. Kevin Wood, a research scientist at the NOAA Pacific Marine Environmental Laboratory – University of Washington Joint Institute for the Study of the Atmosphere and Ocean, sits for a portrait at the NOAA campus in Seattle, Washington, U.S., December 6, 2019. Wood is the lead investigator on the Old Weather Arctic project, which uses volunteer-collected historical weather data from thousands of pages of ships' logs to help inform climate projections. Picture taken December 6, 2019. To match Special Report CLIMATE-CHANGE/ICE-SHIPLOGS REUTERS/Lindsey Wasson

Old Weather group volunteer Michael Purves poses for a photograph at Clover Point Park in Victoria, British Columbia, Canada, November 13, 2019. A group of far-flung volunteers called Old Weather is painstakingly extracting data from the handwritten logbooks of 19th-century ships to help us understand how the Earth's climate is changing. Founded a decade ago, Old Weather's volunteers have accumulated an astonishing 4 million observations of weather and ice, taken mostly from the logbooks of ships plying northern or Arctic routes. Picture taken November 13, 2019. To match Special Report CLIMATE-CHANGE/ICE-SHIPLOGS. REUTERS/Kevin Light

Old Weather group volunteer Michael Purves poses for a photograph at his laptop in his home office in Victoria, British Columbia, Canada, November 13, 2019. A group of far-flung volunteers called Old Weather is painstakingly extracting data from the handwritten logbooks of 19th-century ships to help us understand how the Earth's climate is changing. Founded a decade ago, Old Weather's volunteers have accumulated an astonishing 4 million observations of weather and ice, taken mostly from the logbooks of ships plying northern or Arctic routes. Picture taken November 13, 2019. To match Special Report CLIMATE-CHANGE/ICE-SHIPLOGS REUTERS/Kevin Light

Dr. Kevin Wood, a research scientist at the NOAA Pacific Marine Environmental Laboratory – University of Washington Joint Institute for the Study of the Atmosphere and Ocean, stands for a portrait at the NOAA campus in Seattle, Washington, December 6, 2019. Wood is the lead investigator on the Old Weather Arctic project, which uses volunteer-collected historical weather data from thousands of pages of ships' logs to help inform climate projections. Picture taken December 6, 2019. To match Special Report CLIMATE-CHANGE/ICE-SHIPLOGS REUTERS/Lindsey Wasson

Dr. Kevin Wood, a research scientist at the NOAA Pacific Marine Environmental Laboratory – University of Washington Joint Institute for the Study of the Atmosphere and Ocean, stands for a portrait at the NOAA campus in Seattle, Washington, U.S., December 6, 2019. Wood is the lead investigator on the Old Weather Arctic project, which uses volunteer-collected historical weather data from thousands of pages of ships' logs to help inform climate projections. Picture taken December 6, 2019. To match Special Report CLIMATE-CHANGE/ICE-SHIPLOGS REUTERS/Lindsey Wasson

Helen Julian, a volunteer from the Old Weather group, poses for a photograph in Darlington, Britain, December 6, 2019. A group of far-flung volunteers called Old Weather is painstakingly extracting data from the handwritten logbooks of 19th-century ships to help us understand how the Earth's climate is changing. Founded a decade ago, Old Weather's volunteers have accumulated an astonishing 4 million observations of weather and ice, taken mostly from the logbooks of ships plying northern or Arctic routes. Picture taken December 6, 2019. To match Special Report CLIMATE-CHANGE/ICE-SHIPLOGS. REUTERS/Lee Smith

Helen Julian, a volunteer from the Old Weather group, poses for a photograph in Darlington, Britain, December 6, 2019. A group of far-flung volunteers called Old Weather is painstakingly extracting data from the handwritten logbooks of 19th-century ships to help us understand how the Earth's climate is changing. Founded a decade ago, Old Weather's volunteers have accumulated an astonishing 4 million observations of weather and ice, taken mostly from the logbooks of ships plying northern or Arctic routes. Picture taken December 6, 2019. To match Special Report CLIMATE-CHANGE/ICE-SHIPLOGS. REUTERS/Lee Smith

Dr. Kevin Wood, a research scientist at the NOAA Pacific Marine Environmental Laboratory – University of Washington Joint Institute for the Study of the Atmosphere and Ocean, stands for a portrait at the NOAA campus in Seattle, Washington, December 6, 2019. Wood is the lead investigator on the Old Weather Arctic project, which uses volunteer-collected historical weather data from thousands of pages of ships' logs to help inform climate projections. Picture taken December 6, 2019. To match Special Report CLIMATE-CHANGE/ICE-SHIPLOGS REUTERS/Lindsey Wasson

Dr. Kevin Wood, a research scientist at the NOAA Pacific Marine Environmental Laboratory – University of Washington Joint Institute for the Study of the Atmosphere and Ocean, stands for a portrait at the NOAA campus in Seattle, Washington, U.S., December 6, 2019. Wood is the lead investigator on the Old Weather Arctic project, which uses volunteer-collected historical weather data from thousands of pages of ships' logs to help inform climate projections. Picture taken December 6, 2019. To match Special Report CLIMATE-CHANGE/ICE-SHIPLOGS REUTERS/Lindsey Wasson

Old Weather group volunteer Michael Purves poses for a photograph at Clover Point Park in Victoria, British Columbia, Canada, November 13, 2019. A group of far-flung volunteers called Old Weather is painstakingly extracting data from the handwritten logbooks of 19th-century ships to help us understand how the Earth's climate is changing. Founded a decade ago, Old Weather's volunteers have accumulated an astonishing 4 million observations of weather and ice, taken mostly from the logbooks of ships plying northern or Arctic routes. Picture taken November 13, 2019. To match Special Report CLIMATE-CHANGE/ICE-SHIPLOGS REUTERS/Kevin Light

Old Weather group volunteer Michael Purves poses for a photograph at Clover Point Park in Victoria, British Columbia, Canada, November 13, 2019. A group of far-flung volunteers called Old Weather is painstakingly extracting data from the handwritten logbooks of 19th-century ships to help us understand how the Earth's climate is changing. Founded a decade ago, Old Weather's volunteers have accumulated an astonishing 4 million observations of weather and ice, taken mostly from the logbooks of ships plying northern or Arctic routes. Picture taken November 13, 2019. To match Special Report CLIMATE-CHANGE/ICE-SHIPLOGS REUTERS/Kevin Light

Old Weather group volunteer Michael Purves poses for a photograph at Clover Point Park in Victoria, British Columbia, Canada, November 13, 2019. A group of far-flung volunteers called Old Weather is painstakingly extracting data from the handwritten logbooks of 19th-century ships to help us understand how the Earth's climate is changing. Founded a decade ago, Old Weather's volunteers have accumulated an astonishing 4 million observations of weather and ice, taken mostly from the logbooks of ships plying northern or Arctic routes. Picture taken November 13, 2019. To match Special Report CLIMATE-CHANGE/ICE-SHIPLOGS REUTERS/Kevin Light

Old Weather group volunteer Michael Purves poses for a photograph at Clover Point Park in Victoria, British Columbia, Canada, November 13, 2019. A group of far-flung volunteers called Old Weather is painstakingly extracting data from the handwritten logbooks of 19th-century ships to help us understand how the Earth's climate is changing. Founded a decade ago, Old Weather's volunteers have accumulated an astonishing 4 million observations of weather and ice, taken mostly from the logbooks of ships plying northern or Arctic routes. Picture taken November 13, 2019. To match Special Report CLIMATE-CHANGE/ICE-SHIPLOGS REUTERS/Kevin Light

Old Weather group volunteer Michael Purves poses for a photograph at Clover Point Park in Victoria, British Columbia, Canada, November 13, 2019. A group of far-flung volunteers called Old Weather is painstakingly extracting data from the handwritten logbooks of 19th-century ships to help us understand how the Earth's climate is changing. Founded a decade ago, Old Weather's volunteers have accumulated an astonishing 4 million observations of weather and ice, taken mostly from the logbooks of ships plying northern or Arctic routes. Picture taken November 13, 2019. To match Special Report CLIMATE-CHANGE/ICE-SHIPLOGS. REUTERS/Kevin Light

Old Weather group volunteer Michael Purves poses for a photograph in his home office in Victoria, British Columbia, Canada, November 13, 2019. A group of far-flung volunteers called Old Weather is painstakingly extracting data from the handwritten logbooks of 19th-century ships to help us understand how the Earth's climate is changing. Founded a decade ago, Old Weather's volunteers have accumulated an astonishing 4 million observations of weather and ice, taken mostly from the logbooks of ships plying northern or Arctic routes. Picture taken November 13, 2019. To match Special Report CLIMATE-CHANGE/ICE-SHIPLOGS. REUTERS/Kevin Light

Old Weather group volunteer Michael Purves poses for a photograph on his front porch Victoria, British Columbia, Canada, November 13, 2019. A group of far-flung volunteers called Old Weather is painstakingly extracting data from the handwritten logbooks of 19th-century ships to help us understand how the Earth's climate is changing. Founded a decade ago, Old Weather's volunteers have accumulated an astonishing 4 million observations of weather and ice, taken mostly from the logbooks of ships plying northern or Arctic routes. Picture taken November 13, 2019. To match Special Report CLIMATE-CHANGE/ICE-SHIPLOGS. REUTERS/Kevin Light

Old Weather group volunteer Michael Purves poses for a photograph on his front porch in Victoria, British Columbia, Canada, November 13, 2019. A group of far-flung volunteers called Old Weather is painstakingly extracting data from the handwritten logbooks of 19th-century ships to help us understand how the Earth's climate is changing. Founded a decade ago, Old Weather's volunteers have accumulated an astonishing 4 million observations of weather and ice, taken mostly from the logbooks of ships plying northern or Arctic routes. Picture taken November 13, 2019. To match Special Report CLIMATE-CHANGE/ICE-SHIPLOGS. REUTERS/Kevin Light

Old Weather group volunteer Michael Purves poses for a photograph looking over the Pacific Ocean from the Dallas Road Waterfront Trail in Victoria, British Columbia, Canada, November 13, 2019. A group of far-flung volunteers called Old Weather is painstakingly extracting data from the handwritten logbooks of 19th-century ships to help us understand how the Earth's climate is changing. Founded a decade ago, Old Weather's volunteers have accumulated an astonishing 4 million observations of weather and ice, taken mostly from the logbooks of ships plying northern or Arctic routes. Picture taken November 13, 2019. To match Special Report CLIMATE-CHANGE/ICE-SHIPLOGS REUTERS/Kevin Light

Old Weather group volunteer Michael Purves poses for a photograph at Clover Point Park in Victoria, British Columbia, Canada, November 13, 2019. A group of far-flung volunteers called Old Weather is painstakingly extracting data from the handwritten logbooks of 19th-century ships to help us understand how the Earth's climate is changing. Founded a decade ago, Old Weather's volunteers have accumulated an astonishing 4 million observations of weather and ice, taken mostly from the logbooks of ships plying northern or Arctic routes. Picture taken November 13, 2019. To match Special Report CLIMATE-CHANGE/ICE-SHIPLOGS REUTERS/Kevin Light

The road along the Russian - Norway border is seen in Pasvik valley, Finnmark county, Norway, October 23, 2019. REUTERS/Maxim Shemetov

A group of reindeers cross the road along the Russian - Norway border in Pasvik valley, Finnmark county, Norway, October 23, 2019. REUTERS/Maxim Shemetov

Employees work at Kimek shipyard in Kirkenes, Norway, October 24, 2019. REUTERS/Maxim Shemetov

A pier and fishing gear storage is seen at Kimek shipyard in Kirkenes, Norway, October 24, 2019. REUTERS/Maxim Shemetov

A general view of houses in Kirkenes, Norway, October 24, 2019. REUTERS/Maxim Shemetov

A road sign lies on the grass in Kirkenes, Norway, October 26, 2019. REUTERS/Maxim Shemetov

U.S. marines from Fox Company, 2nd Battalion, 6th Marine Regiment, part of the Marine Rotational Force - Europe, take part in "Reindeer 2" Norwegian-U.S. military drill in Setermoen, Norway, October 29, 2019. REUTERS/Stoyan Nenov

The Aurora Borealis (Northern Lights) is seen over the World War II memorial in Abram Mys outside Murmansk, Russia, October 27, 2019. REUTERS/Maxim Shemetov

A Norwegian soldier is seen atop a tank during "Reindeer 2" Norwegian-U.S. military drill in Setermoen, Norway, October 29, 2019. REUTERS/Stoyan Nenov

A Norwegian soldier is seen through the window of a military vehicle during "Reindeer 2" Norwegian-U.S. military drill in Setermoen, Norway, October 29, 2019. REUTERS/Stoyan Nenov

Soldiers from the Combat Support Squadron of the First Battalion of the Northern Brigade of the Norwegian Army pack their camp in the morning during "Reindeer 2" Norwegian-U.S. military drill in Setermoen, Norway, October 30, 2019. REUTERS/Stoyan Nenov

Soldiers from the Combat Support Squadron of the First Battalion of the Northern Brigade of the Norwegian Army warm themselves around a fire in their camp during "Reindeer 2" Norwegian-U.S. military drill in Setermoen, Norway, October 29, 2019. REUTERS/Stoyan Nenov

Soldiers from Second Tank Squadron of the First Battalion of the Northern Brigade of the Norwegian Army prepare their tank during "Reindeer 2" Norwegian-U.S. military drill in Setermoen, Norway, October 30, 2019. REUTERS/Stoyan Nenov

A soldier from Second Tank Squadron of the First Battalion of the Northern Brigade of the Norwegian Army is seen atop of a tank during "Reindeer 2" Norwegian-U.S. military drill in Setermoen, Norway, October 30, 2019. REUTERS/Stoyan Nenov

A tank from Second Tank Squadron of the First Battalion of the Northern Brigade of the Norwegian Army is seen during "Reindeer 2" Norwegian-U.S. military drill in Setermoen, Norway, October 30, 2019. REUTERS/Stoyan Nenov

An employee walks past steel constructions at Olen Betong factory outside Murmansk, Russia, October 30, 2019. REUTERS/Maxim Shemetov

A general view on the coal harbour and the centre of Murmansk, Russia, October 27, 2019. REUTERS/Maxim Shemetov

Concrete slabs are stored at Olen Betong factory outside Murmansk, Russia, October 30, 2019. REUTERS/Maxim Shemetov

A general view on the centre of Murmansk, Russia, October 27, 2019. REUTERS/Maxim Shemetov

An observational tower overlooks the Norway-Russia border from the Norwegian side in Pasvik valley, Finnmark county, Norway, October 23, 2019. REUTERS/Maxim Shemetov SEARCH "NORWAY-RUSSIA BORDER" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES.

Buildings stand in the centre of Murmansk, Russia, October 27, 2019. REUTERS/Maxim Shemetov SEARCH "NORWAY-RUSSIA BORDER" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES.

Freight trains pass through Murmansk, Russia, October 28, 2019. REUTERS/Maxim Shemetov SEARCH "NORWAY-RUSSIA BORDER" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES.

Norwegian and Russian students play a game of volleyball during a PE lesson at the Russia-Norway school in Murmansk, Russia, October 29, 2019. REUTERS/Maxim Shemetov SEARCH "NORWAY-RUSSIA BORDER" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES.

People walk through the snow on a street in Murmansk, Russia, October 30, 2019. REUTERS/Maxim Shemetov SEARCH "NORWAY-RUSSIA BORDER" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES.

A sign with a picture of Vladimir Putin that reads "Dear colleagues, keep clean!" is hung amongst tools at the Olen Betong factory outside Murmansk, Russia, October 30, 2019. REUTERS/Maxim Shemetov SEARCH "NORWAY-RUSSIA BORDER" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES.

People cross a road in Murmansk, Russia, October 28, 2019. REUTERS/Maxim Shemetov SEARCH "NORWAY-RUSSIA BORDER" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES.

Norwegian and Russian students attend a PE lesson at the Russia-Norway school in Murmansk, Russia October 29, 2019. REUTERS/Maxim Shemetov SEARCH "NORWAY-RUSSIA BORDER" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES.

An employee welds a steel construction at the Olen Betong factory in Murmansk, Russia, October 30, 2019. REUTERS/Maxim Shemetov SEARCH "NORWAY-RUSSIA BORDER" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES.