Arctic sea ice shrinks to fourth lowest extent on record

Polar region's sea ice continues long term decline since satellite monitoring began in the 1970s, driven by warming temperatures in atmosphere and ocean

Ice coverage in the Arctic this year shrunk to its fourth lowest extent on record, US scientists have announced.

The National Snow and Ice Data Centre (NSIDC) in Boulder, Colorado, said the ice reached a low of 4.41m sq km (1.70m sq miles) on 11 September in what experts said was a clear indicator of climate change.