Nasa scientists observe Arctic sea ice changes – video

Satellite footage shows seasonal ice melt in the Arctic Ocean melting in the summer. The frozen ice caps melt throughout summer in the Northern Hemisphere until they begin to re-freeze as temperatures get colder in mid-September. Nasa says the sea ice extent in the Arctic is below average for the last 30 years. The average ice cover has decreased by 18% since 2010 to 2.31 million square miles