Arctic ice cap, mostly frozen salt water, covered a larger portion of the north pole ten years ago. NASA's pictures taken over ten years above shows dangerously receding ice line. NASA has monitored the ice retreat over thirty years now and has reported steady decline in Arctic sea ice.

The rate of decrease of ice cap remained fairly low until the end of last century. The decline seems to have accelerated rapidly from the start of the twenty first century.

The sea ice was the lowest in September 2002 but hasn't climbed back to the long-term average ever since.

Sep–Mar Sep Avg Mar Avg
1979–2000 7.0 15.7
1999–2000 6.2 15.3
2000–2001 6.3 15.6
2001–2002 6.8 15.4
2002–2003 6.0 15.5
2003–2004 6.1 15.1
2004–2005 6.0 14.7
2005–2006 5.6 14.4
2006–2007 5.9 14.6
2007–2008 4.3 15.2
2008–2009 4.7 15.2

Natural temperature cycles coupled with green house gas emissions have contributed to the decline.

--
I Am New,
Krish Murali Eswar.
Picture Courtesy: NASA Earth Observatory