A team of scientists has warned that the record amount of Arctic ice melting this year could have a profound impact on the global environment.
Norwegian researchers have reported that the sea ice is becoming significantly thinner and more vulnerable.
Last month, the annual thaw of the region's floating ice reached the lowest level since satellite monitoring began, more than 30 years ago.
The Norwegian Polar Institute (NPI) is at the forefront of Arctic research and its international director, Kim Holmen, told the BBC that the speed of the melting was faster than expected.
"It is a greater change than we could even imagine 20 years ago, even 10 years ago," the BBC quoted Dr Holmen as saying.
"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," Holmen said.
Key data on the ice comes from satellites but also from measurements made by a range of different techniques - a mix of old and new technology harnessed to help answer the key environmental questions of our age.