Not trusting them is reasonable, but then where does that leave you? You don't know then whether they're underestimating or overestimating things. I'm strongly in favor of building a prior from the geological record and leaning on that as much or more than the models, but that doesn't lead to a very different conclusion.
I guess that, at least compared to society in general, I'm a cognitive nihilist? I highly doubt that it is in our power to predict with useful accuracy something as complex as climate. If I'm not mistaken, we're still having problems modelling stuff a billion times less complex than climate (such as an air flow in turbines etc.)...
Generally, more uncertainty around climate change means you should be more supportive of climate change mitigation rather than less, because it means we can't rule out things that look like the P-T extinction.
There's infinite number of events which we can't rule out. My approach is basically the opposite - if the evidence for something is super-sketchy, maybe we shouldn't spend trillions (or even quadrillions?) on preparing for it.
