I'm thinking about this, and right now I think belief in astrology is the best test:

• Theism correlates with where and when you grew up more than anything else. (ISTM that in Italy, people from the former Kingdom of the Two Sicilies are far more likely to be religious than people from the former Papal States; and I think that in the Republic of Ireland younger people are less likely to be religious than older people. More generally, there are many more atheists in Europe than elsewhere.)
• As for anthropogenic global warming, I just don't think the typical person has encountered enough evidence (of the kind they can understand) to have strong grounds to decide one way or the other, so different beliefs will mostly be due to different priors and/or motivated cognition, the former telling us nothing and the latter telling us the person's political affiliation more than anything else.
• In the case of marijuana legalization (apart from the issue of value judgements), what I see confuses me: ISTM that most people above a certain age are against it and most people below a certain age (except politically right-wing ones) are in favour of it, but that would mean that either 1) support for marijuana legalization advances one funeral at a time, and hence ought to be larger now than 15 years ago than 30 years ago than 45 years ago, or 2) most people change their minds at a certain point in their lives, neither of which I've observed. I suspect that there's some kind of selection bias in the young people I know and the old people I know. (Also, signalling probably plays a helluva part in this, so maybe the old people who claim they never supported marijuana legalization are just lying.)
• I can think of no social, geographical, or political factor which would substantially correlate with belief in astrology, like, at all. (Maybe I just lack imagination, though.)

BTW, I've noticed that among people I know, belief in God and belief in AGW appear to be strongly negatively correlated among physics professors, but not among the general population (any more than you'd expect from them correlating with right- and left-wing political views respectively, at least). Maybe that's just statistical noise from small sample size (and/or cognitive biases of mine -- it's not like I've given out surveys or made statistics).