Russian gas giant Gazprom announced Wednesday that one of its ships had transported liquified natural gas from Europe to Asia via the Arctic for the first time, in a sign of what a changing climate could mean for global energy markets.

The tanker Ob River operated by Gazprom arrived at the Japanese port of Tobata nearly a month after leaving Norway's Hammerfest terminal on November 7, Gazprom said in a statement.

The tanker was accompanied on its journey by several icebreakers, but the ships came across virtually no ice in the Barents and Kara Seas, and only had to break through 30-centimetre thick "young ice" the rest of the way to the Bering Strait, the Russian gas monopoly said.

"The successful journey of the Ob River allows to count on the full-blown usage of the Northern Sea Route to deliver Russian liquified gas both to the Asia-Pacific region and the European market," Gazprom said.

Russia in recent years has focused its attention on Arctic exploration, and is seeking to explore several vast fields in its Far North, notably on the Yamal peninsula, where one project entails building a gas liquefaction plant.

As global warming leads to the shrinking of the ice cap in the Arctic, opening of the Northern Sea Route means a "shorter delivery time, fuel economy" and fewer piracy risks," among other advantages, Gazprom said.

Russia's environmental groups have cautioned against thoughtless exploration of vulnerable northern territories.

No studies have yet been done on how to clean up oil spills in temperatures of minus 40 degrees Celsius (minus 40 degrees Fahrenheit), said Alexei Knizhnikov, a Moscow-based oil and gas expert at WWF.

If Russia's Yamal project goes through, there could be supertankers going through the Northern Sea Route every three days, drastically increasing traffic through the Arctic, he told AFP.

However "from the point of energy efficiency, such deliveries are better than pipeline gas," especially when compared with building a new Russian pipeline to China, he added.