Pielke Sr. takes apart Michael Mann’s recent interview on climate models with Scientific American.
Prof. Roger Pielke writes,
Mike [Mann] does not properly distinguish between the types of modeling. When airplanes or cars are built, the engineers are testing their models using real world airplanes and cars, as well as with wind tunnel evaluations. They can ground-truth their models.
With respect to atmospheric modeling, numerical modeling prediction of the weather for the coming days is ground-truthing, as the forecasts can be compared with real-world observations just a few days later.
With multi-decadal climate predictions, they can only realistically be tested from past climate conditions, unless we wait for the coming decades to pass. Even in the hindcast mode, however, the global climate models (whether downscaled to regions or not) have failed to predict changes in the statistics of regional climate. I invite any climate scientist to present evidence on my weblog (as an unedited guest post] that refutes this conclusion.