Record minimum for Arctic sea ice...

 Arctic sea ice has reached its minimum extent for the year, setting a record for the lowest summer cover since satellite data collection began.

The 2012 extent has fallen to 3.41 million sq km (1.32 million sq mi) - 50% lower than the 1979-2000 average. Arctic sea ice has long been regarded as a sensitive indicator of changes in the climate. Scientists who have been analysing the startling melt think it is part of a fundamental change.

What is arctic sea ice?