Scientists with the Norwegian Polar Institute said the annual thaw of the region's floating ice reached the lowest level since satellite monitoring began more than 30 years ago.
"It is a greater change than we could even imagine 20 years ago, even 10 years ago," the institute's international director, Kim Holmen, told the BBC. "And it has taken us by surprise and we must adjust our understanding of the system and we must adjust our science and we must adjust our feelings for the nature around us."
Researchers said the scale of the melt could have a long-term effect on Europe's climate, as a massive reduction in sea ice could bring changes in the path of the jet stream, the high-altitude atmospheric winds that guide weather systems, including storms.
"When the Arctic is ice free, it is not white any more and it will absorb more sunlight and that change will influence wind systems and where the precipitation comes," Holmen said. "For northern Europe it could mean much more precipitation, while southern Europe will become drier so there are large scale shifts across the entire continent."