Here’s something really interesting: two comparisons between model ensembles and 3 well known global climate metrics plotted together. The interesting part is what happens in the near present. While the climate models and climate measurements start out in sync in 1979, they don’t stay that way as we approach the present.
A second graph showing 20 year trends is more pronounced.Lucia Liljegren of The Blackboard did both of these, and she writes:
Note: I show models with volcanic forcings partly out of laziness and partly because the period shown is affected by eruptions of both Pinatubo and El Chichon.
Here are the 20 year trends as a function of end year:
One thing stands out clearly in both graphs: in the past few years the global climate models and the measured global climate reality have been diverging.
Lucia goes on to say:
I want to compare how the observed trends fit into the ±95 range of “all trends for all weather in all models”. For now I’ll stick with the volcano models. I’ll do that tomorrow. With any luck, HadCrut will report, and I can show it with March Data. NOAA reported today.
Coming to the rescue was Blackboard commenter Chad, who did his own plot to demonstrate +/- 95% confidence intervals using the model ensembles and HadCRUT. He showed very similar divergent results to Lucia’s plots, starting about 2006.
So the question becomes: is this the beginning of a new trend, or just short term climatic noise? Only time will tell us for certain. In the meantime it is interesting to watch.