Posted by Here’s a graph showing the extent of arctic sea ice as measured directly and indirectly for the last several hundred years:
Solid red line is the reconstructed 40 year smoothed, late-summer Arctic sea ice extent from Kinnard et al. (2011). Shaded area shows 95% confidence interval. Blue dashed line shows modern observations.
This graphic is from Skeptical Science, where you can also download a higher res version and learn more about the background for these data. Also, on that page is a link to a large number of useful graphics related to climate change.
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February 3, 2013
February 4, 2013
, which is now available for the 
