Arctic sea ice has melted to a record low this month, prompting fears that the entire polar ice cap may disappear within decades.
Satellite images of the northern hemisphere's floating sea ice show that the area of ocean covered by the ice during this month was the lowest ever observed by scientists.
It is the fourth consecutive summer that the area covered by the sea ice in the Arctic has shrunk below even the long-term decline, which began at least as far back as the late 1970s.
A gradual loss of sea ice has taken place for a quarter of a century but scientists believe they may be witnessing an acceleration in the melting process because of climate change and a process of "positive feedback" causing a vicious cycle of melting and warming.