Y Safle

I wrote a post yesterday about Martin Durkin’s junk science programme on global warming designed to convince people with no knowledge of the issue that - in his words - global warming is not our fault. I took issue with a number of points, including the graph on which Durkin manipulated temperature data to make it look as though the post war cooling period was much larger than it actually was.

Someone (Jason) commented that my own graph, that I included for comparison, had a trend line that seemed to hide the post war cooling period. The graph had come from a previous article where it was demonstrating that the warming trend had not (contrary to the arguments of some) stopped in 1999. The trend line is superfluous to establishing the deceit of Durkin’s graph.

Whilst the data is quite clear in the graph, demonstrating the point, I considered the point, and thought that it would be better if I construct a new graph, comparing Durkin’s data and at least one well respected source of historic climate data. I have used Crutem 3v, because I had it available after creating the previous graph.

The problem is that Durkin’s data is not published anywhere. The “source: NASA” attribution hides the fact that the graph has been redrawn and in fact now matches no known data set. Thus I carefully used a ruler(!!) to reconstruct the data set from Durkin’s graph. It is not perfect, but it is pretty close. (You can check it against the original included in yesterday’s post).

I then plotted Durkin and the Crutem 3v dataset (which is a bit “wiggly lined” in Durkin’s words). In order to average out the wiggly lines and make it more directly comparable with Durkin’s data, I calculated a 10 year moving average and plotted this.

This average, I think, suggests that Durkin’s dates are a little off in his data - but the shapes do approximate to something similar (a 5 year moving average was too granular for Durkin’s graph).

So here is the complete graph. Click on the thumbnail to see it full size. I have shaded the same area that Durkin shaded - the period of post war cooling due to industrial aerosols prior to the agreements to reduce these. Notice particularly how much more strongly the temperature anomaly grows after this period than in Durkin’s graph. Bear in mind that in Durkin’s graph, his team made up these data for this period.