According to figures from the University of Washington and the University of Illinois, Arctic ice thickness is averaging a little over two metres, down from a little over three metres in 1979.

In 1940, it was reported that Arctic sea ice thickness was two metres, down from three metres in 1900. In other words, the past 35 years have been a repeat of the early part of the century

23 Feb 1940 – THE NORTH POLE. Is it Getting Warmer. | BUNDABER…
By 1958, scientists reported a 50% reduction in volume – and predicted an ice-free Arctic in the next generation.

The Changing Face of the Arctic – The Changing Face of the Arctic – View Article – NYTimes.com
Bottom line is that the Arctic is cyclical, forecasts by Arctic experts are cyclical, they have absolutely no clue what they are talking about – and never did.
The most important thing to note is that starting graphs at the peak year of 1979 without bold warnings or disclaimers, is scientific malfeasance. Based on my reading, I would estimate that ice thickness has done something like this since 1940.
