IPCC Climate Model Projections Diverging from Reality

The plot of the 2007 IPCC (GCM model) temperature projection is presented in green. The red plot represents temperature observations to the end of 2011. It is clear that the green IPCC projection -- with a wide error allowance -- is diverging ever upward from the observed temperatures.

Nicola Scafetta's harmonic model is plotted as a black wavy line surrounded by a blue error range.

Scafetta Harmonic Model WUWT

The [Scafetta] model was able not only to reconstruct the decadal patterns of the temperature since 1850 better than any general circulation model (GCM) adopted by the IPCC in 2007, but it is apparently able to better forecast the temperature decadal/multidecadal pattern observed since 2000. Note that since 2000 my proposed model is a full forecast.

However, will the forecast hold, or my proposed model is just another failed attempt to forecast climate change at least roughly? Time will tell. _WUWT Nicola Scafetta

Scafetta Harmonic Model WUWT
The humorous facet of this affair is that the 2007 IPCC GCM model did very well at "predicting" the climate prior to 2007! It is only after the model was forced to project into the future (rather than the past) that its projections began to swing widely away from actual observed temperatures.

Notice how the Scafetta harmonic model temperatures seem to dive abruptly after the year 2024.

So just using your eyeballs to evaluate the comparative trends, which model appears to match observed temperatures better: The IPCC's highly sophisticated global circulation model (GCM), which is very sensitive to rising CO2 levels and positive feedbacks, or Scafetta's much simpler harmonic model, which is based instead on multiple overlapping natural cycles?