Melting Sea Ice
The ice over the Arctic Ocean is shrinking at record rates this year, a stark signal of global warming, scientists say. How bad is it? Watch this striking animated GIF of the past few decades' of ice shrinkage from climate change blog Open Mind .
Using data from the University of Illinois' Cryosphere Today , blogger Tamino animated the changes in area of the Arctic Sea ice from 1980 to 2012. In the summer, the ice melts more before refreezing in the winter, which explains the dip and rise.
As you can see, the line gets steeper and steeper as time passes, and the area gets lower and lower, showing how the ice is diminishing due to rising temperatures. Whether or not you think global warming is caused by humans, the evidence is clear that ice is no longer refreezing to its previous levels.