"I can make a model tie my shoe laces": Because the models all provide sham estimates, Pindyck advocates throwing them out and taking our best shots at answers

Lawrence Solomon: Model mockery | Financial Post

Why are they useless? For one thing, the “modeler has a great deal of freedom in choosing [his inputs]. Thus these models can be used to obtain almost any result one desires.” To highlight the absurdity of this freedom, Pindyck mentions that a “colleague of mine once said ‘I can make a model tie my shoe laces.’”
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Heaping ridicule on the methodology of the modelers, Pindyck refers to an IPCC survey of 22 peer-reviewed published studies of climate sensitivities that was summarized into a meaningless graph. The modelers then used this IPCC graph in their subsequent models. “But where did the IPCC get those numbers? From its own survey of several IAMs. Yes, it’s a bit circular.”

Because the models all provide sham estimates, Pindyck advocates throwing them out and taking our best shots at answers. “Perhaps the best we can do is come up with rough, subjective estimates of the probability of a climate change sufficiently large to have a catastrophic impact … Of course this approach does not carry the perceived precision that comes from an IAM-based analysis, but that perceived precision is illusory.”