Each northern summer, the Arctic ice melts a bit (well a lot actually) and in winter it grows back. But recently it's been melting much more than usual. This year, the ice has reached its lowest point ever (even lower than last year).
Various agencies measure it different ways, but all agree this year's the lowest.
The Polar Research Group has an interactive graph of ice area throughout each year (the yellow is 2012 so far).
(The difference between the highpoint in March and the low point is greater than the area of Australia, Canada or any nation other than Russia.)
The National Snow and Ice Data Center has a daily image update of the area of ocean containing ice.
The Japanese Areospace Exploration Agency compare the last few years to recent decades (each one lower than the one before).
And then saw this summary which plots the minimum volume for each year. It seems that due to the thickness decreasing, the volume is dropping even more drastically than the area.
So why is this important? (Apart from confirming that climate change is already well and truly upon us.) It is important because it accelerates what is called a 'feedback loop'.
Where sunlight previously reflected off the ice, it is now absorbed by the water. This means the globe warms faster, which mean ice melts even faster, which means the globe warms even faster, which means ice melts ... etc etc.
The effect of having so much less ice has been compared to an addition 20 years worth of carbon dioxide.
It's now no longer a question of if the Artic will lose all its ice, but when.
[More information, and effects, are listed by the Climate Commission]
PS. Ironically, on the same day the Arctic reached it's lowest point, Britain was discussing plans to expand it's biggest airport, and the Republican convention in the USA was delayed by extreme weather (the kind that is exacerbated by climate change).
Also, something i find a bit sad is that people can now gamble on how fast all this takes place.
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