In preparation for the Easter Hansen Was Wrong in 1988 offensive Eli went back and looked at an old post. As Hansen said
The climate model we employ has a global mean surface air equilibrium sensitivity of 4.2 C for doubled CO2. Other recent GCMs yield equilibrium sensitivities of 2.5-5.5 C.....
Forecast temperature trends for time scales of a few decades or less are not very sensitive to the model's equilibrium climate sensitivity (reference provided). Therefore climate sensitivity would have to be much smaller than 4.2 C, say 1.5 to 2 C, in order for us to modify our conclusions significantly.Eli pointed out that
We are getting to the point, twenty years on, where the high estimate of climate sensitivity is making itself felt. OTOH, the 1988 paper estimated the forcings slightly on the low side. The result was a pretty good prediction. Definitely in the class of useful models.We are also at the point where Scenario C, the one where CO2 went to zilch in 2000, would, according to the 1988 model, plateau, but one would expect that this far on the 1988 predictions would begin to look a bit too high because of the large climate sensitivity.
So in the spirit of the thing, allow Eli to plot the 1988 model data, let's throw in the GISSTemp temperature anomalies, as was done in the 1988 paper, basing the anomaly on the 1951-1980 period.
UPDATE: As any thinking bunny might expect, for this Nick Stokes has a better gimmick, but he should work on the background. Eli understands that Pat and Chip could loan him their Photoshop.