Turn Down Those Knobs

Classic Steve McIntyre blog-post, well worth reading in its entirety:

… all the GCMs that underperform the Callendar formula run too hot. It seems evident to me (and I do not claim that this observation is original) that the range of IPCC models do not fully sample the range of physically possible or even plausible GCMs at lower sensitivities. Perhaps it’s time that the climate community turned down some of the tuning knobs.
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