There was something else that was odd about the Arctic sea ice volume graph that was used in the Benton lecture of 2018 (see previous post). Besides the ambuigity of the last data point and its weird position relative to the previous data points, there also seemed to be something a bit off at the 2012 data point (the lowest point of the graph). When I tried to overlay the Benton lecture graph over the actual annual minimum volume graph, it seemed that the 2012 data point was situated somewhat lower on the Benton lecture graph than it was in the PIOMAS dataset (the dataset this graph was based on). It didn’t seem to be that much at the time, so I wasn’t initially too bothered about it.
I later decided nevertheless to look into it and digitized the whole graph, instead of just looking at that last data point as I did in previous post. This indeed showed that the 2012 value was somewhat lower in the Benton lecture graph.
It also showed that both graphs are identical until 2009, but there is a small phase-shift from 2010 until 2012: