Identifying bias. A Bayesian analysis of suspicious agreement between beliefs and values.

Having beliefs and values converge to the truth is the desired outcome. The trick is knowing if the convergence is to the truth, or just the shortest line projection between the two.

Whether in science or law, truth producing activities tend to be adversarial. If done honestly and with commitment, wtih capable adversaries, that's a pretty good system. If you care enough to spend the effort, and have capable and similarly committed adversaries available, I think that's a much better recipe for coming to the truth than stewing in the juices of your own beliefs and the beliefs of your tribe.

Why is politics one dimensional? Many people say that this is the result of the two party system, forcing people into coalitions.

I believe it's the other way round. People were dividing others to "us" and "them" long before political parties were invented.

I'd say that "us" and "them" is hardcoded in people. We also have a bias to imagine that all our enemies are in some sense the same (so there is only one "them", instead of "them1", "them2", "them3"...) Most people are probably bad at imagining that more then two options are possible.

Also, there are often binary decisions to make: Someone proposes a new change of law in the parliament, do you vote "yes" or do you vote "no"?

If parties are coalitions, you might expect different coalitions in different countries. Correlations between factual beliefs might switch between countries. But I do not think this happens.

Sure it does. For example, in Slovakia, the only political party that supports legalization of marijuana and gay marriage is classified as right-wing (their political opponents love to say "extreme right-wing"), because they also happen to support free market. If I understand it correctly, in USA marijuana and gay marriage are generally considered left-wing issues.

this seems to ignore the possibility of deriving one's values from one's beliefs

The possibility (or something closely related) is raised in the section headed "Causes of agreement between political views and factual beliefs" -- it's option (b) in the list near the start of that section. But that option gets dismissed rather rapidly. (Too rapidly, I think.)

Climate change is extremely convenient for the left to promote leftist policies

In so far as this is true, it is also true that climate change denial[1] is extremely convenient for the right. (And vice versa.)

[1] I intend this here to mean simply "denying" rather than "denying in the face of what ought to be overwhelming evidence"; there doesn't seem to be a neutral way of putting it.

This is a general phenomenon: if there are rival positions X and Y on a factual matter, which if true would support rival positions P and Q on a matter of policy, then you may suspect partisans of P of bias when they assert X, but you may equally suspect partisans of Q of bias when they assert Y. So if you are not yourself very partisan, what difference should this make to your opinions about X versus Y? It should make you treat someone's opinion about X/Y as less informative in so far as they have a partisan position on P/Q that would explain it. (But bear in mind that the causation may go X/Y -> P/Q rather than the other way around, so the appropriate discounting is less than you might naively think.)

So, in this case, you might reasonably be very suspicious about American politicians' statements about climate change, because in the US the issue is very politicized. So, where else should you look?

• Outside the US. It's really only in the US that such a tight relationship between politics and opinion on climate change is present. Outside the US, even right-wing politicians (whom you might, in terms of the model here, expect to have a strong bias against belief in anthropogenic climate change) generally agree that the climate is warming because of human industrial activity, and they generally favour taking measures to reduce the warming. (But "conservative parties do not challenge coal or petroleum in countries with large reserves of these resources".)
• The opinions of actual climate scientists. Being a scientist is of course no guarantee of being unbiased, and there are ways for scientific institutions to be biased even when individual scientists are not.[2] But reducing the influence of bias is a large part of what scientific methods and institutions are for, and probably most climate scientists got into the field before it was as political as it is now. (And many of them are outside the US; see above.) Well, it appears that climate scientists are pretty close to unanimous about the reality of anthropogenic climate change.
• People whose opinions on politics and climate change don't "match". E.g., take a look at the results here. It appears that about 24% of conservative Republicans accept anthropogenic climate change, and about 19% of liberal Democrats don't. Maaaaybe that's evidence that anthropogenic climate change is real. (But you need to be careful about this sort of thing: it could be that the political bias is stronger one way than the other. For what it's worth, my guess is that on this issue the conservative->no-ACC link is stronger than the liberal->ACC link, which would mean that that discrepancy is evidence for ACC, but I don't have any very compelling arguments to support that guess.)

[2] E.g., a wealthy entity -- a government, an industry consortium, etc. -- might provide funding for climate research in ways that happen to favour employment of scientists whose views match the wealthy entity's. Those scientists may individually be perfectly unbiased, following the evidence wherever it leads, but the process that selects them may be biased.