I was wondering how long it would be until the AGW issue was directly broached on a top-level post. Here I will state my views on it.

First, I want to fend off the potential charge of motivated cognition. I have spent the better part of two years criticizing fellow "libertarians" for trivializing the issue, and especially for their rationalizations of "Screw the Bengalis" even when they condition on AGW being true. I don't have the links gathered in one place, but just look here and here, and linked discussions, for examples.

That said, here are the warning signs for me (this is just to summarize, will gather links later if necessary):

1) Failed predictions. Given the complexity of the topic, your models inevitably end up doing curve-fitting. (Contrary to a popular misconception, they do not go straight from "the equations they design planes from" to climate models.) That gives you significant leeway in fitting the data to your theory. To be scientific and therefore remove the ability of humans to bias the data, it is vital that model predictions be validated against real-world results. They've failed, badly: they predicted, by existing measures of "global temperature", that it would be much higher than it is now.

2) Anti-Bayesian methodology accepted as commonplace. As an example, regarding the "hide the decline" issue with the tree rings, here's what happened: Scientists want to know how hot it was millenia ago. Temperature records weren't kept then. So, they measure by proxies. One common proxy is believed to be tree rings. But tree rings don't match the time period in which we have the best data.

The correct procedure at this point is to either a) recognize that they aren't good proxies, or b) include them in toto as an outlier data point. Instead, what they do is to keep all the data points that support the theory, and throw out the rest, calling it a "divergence problem", and further, claim the remaining points as additional substantiation of the theory. Do I need to explain here what's wrong with that?

And yet the field completely lacks journals with articles criticizing this.

3) Error cascades. Despite the supposed independence of the datasets, they ultimately come from only a few interbred sources, and further data is tuned so that it matches these data sets. People are kept out of publication, specifically on the basis that their data contradicts the "correct" data.

Finally, you can't just argue, "The scientists believe AGW, I trust scientists, ergo, the evidence favors AGW." Science is a method, not a person. AGW is credible to the exent that there is Bayesian evidence for it, and to the extent scientists are following science and finding Bayesian evidence. The history of the field is a history of fitting the data to the theory and increasing pressure to make sure your data conforms to what the high-status people decreed is correct.

Again, if the field is cleansed and audited and the theory turns out to hold up and be a severe problem, I would love for CO2 emissions to finally have their damage priced in so that they're not wastefully done, and I pity the fools that demand Bengalis go and sue each emitter if they want compensation. But that's not where we are.

And I don't think it's logically rude to demand that the evidence adhere to the standard safeguards against human failings.