What about before 1979?
Haven't pulled up any figures, but searching for "ice cap area over 100 years" gave me this as the first result:
http://en.wikipedia.org/wiki/Retreat_of_glaciers_since_1850And as with
any set of data, I'd be interested to know:
-what are the units of the y-axis
-what
is the data on the y-axis representing (I guess it's area of ice, but I don't know)
-where/how was it obtained
-is it the entire set of data
-where are the measurements from
-were any of the data defined as outliers and removed
...and so on.
Until these things are known, that chart is essentially meaningless.