Arctic sea ice is melting even faster than last year, despite a cold winter.

Data from the US National Snow and Ice Data Center (NSIDC) shows that the year began with ice covering a larger area than at the beginning of 2007.

But now it is down to levels seen last June, at the beginning of a summer that broke records for sea ice loss.

Scientists on the project say that much of the ice is so thin that it melts easily, and the Arctic may be ice-free in summer within five to 10 years.