I’m going to update this graph every now and then.
There are 12 lines on this graph.
The colorful squiggles up along the top are the first ten years of Arctic Sea ice extent for the period for which we have really good data. So this is 1979 – 1988. There is reason to believe that this is the “normal” sea ice extent track over the year from which we have seen significant deviation over recent decades.
The dark thick line is the average of all of the years from 1979 to 2010. Notice that the first ten years are all above the average except for a few little bits.
The partial line below all of the other lines is the current year, ticking along. I think this graphic provides a good perspective on Arctic Sea ice because we can watch the current state of the ice in comparison to what is reasonably described as “normal.” (I discuss this more here.)
I’ll replace this graphic now and then and re-tweet and re-facebook the post so it all stays in one place. If I’ve not done that in a while and you want me to do it, just let me know.
Data and graphic are from here.