Science does not depend on majority vote. Truth will out, no matter how many people speak lies. So why do I take guidance from the consensus in regards to global warming?
Well, really, I don't. It's more a starting point. Here's how I really came to my conclusions.
Ideally, of course, I would research it myself and draw my own conclusions from the data. Sadly, I have neither the expertise, the training, or the time to do that. So I have to turn to those who do - the experts in the related fields.
That's where the consensus comes in. Just as I don't have time or expertise to research ot myself, I am equally unfit to judge the relative arguments. Under the basic principles of science and peer review, the conclusions shared by an overwhelming majority of scientists are generally the best available explanations for the data. Not necessarily "right" - but most likely to be closer to the truth than any other explanation out there.
For this issue, though, even the consensus seems fuzzy. I'm pretty sure that it is intentionally obscured by one side, so I'm already leaning towards the other - but let's abstract the process one step further, as a check. Let me look at who I know is lying.
I can hear my right-leaning friends and relatives now - "Al Gore! He's lying! He's just in it for the money!" Well, maybe so. The problem is, his investments make just as much sense, maybe even more, if he truly believes man-made global warming is fact. Did he put his mouth where his money is, or vice versa? I don't know, and neither do you.
There's some lies in the arguments that are easier to spot and confirm, though. First are the frequent petitions, conferences, and so forth that claim to show the growing opposition to the scientific consensus. Every one I've looked into, however, shares some common flaws -
they include people with no relevant expertise. One of them accepted participation from anyone with a science degree...even just a Bachelors of Computer Science. None of them appear to limit their participants to just those who have actually studied relevant subjects.
They often include people who never agreed to participate. This includes using deceptive questions to claim that support for one concept (Should we continue to research man-made global warming?) is also support for a more extreme idea (Is the consensus on global warming overblown?). In extreme cases, people have been added to the lists based on out-of-context statements in their published works - and have been kept on the lists even after they specifically requested to be removed. In one really extreme case, some of the people added to the list were dead!
In any event, even if we were to blindly accept their lists of "experts" who claim global warming is a myth...they are an insignificant percentage of people worldwide with the same qualifications. We can use their standards - include anyone with a B.S. degree - and their claim of 31,000 signers gets drowned in the millions of people worldwide with such degrees. Or we can limit our consideration to only those with relevant training and experience - in which case the vast majority of their side drops out, leaving only a few well-publicized scientists bucking the conclusions of their peers.
Other common tactics include the use of misleading statistics. Often a report will note two data points - say, a recent average temperature, and an equivalent reading from some years or decades past. Lo and behold, the two temperatures are virtually the same - the more recent might even be colder! Obviously, the Earth is not warming at all. On further, deeper investigation, though, one often finds some missing elements. It may turn out that the data points listed were from one location, while other locations showed significant warming over the same period. Or a closer look at the entire series of data will show that the latest reading is an outlier, much lower than the trend, and the carefully selected earlier reading was a higher-than-normal outlier - a trend line considering only those two points shows no change or even slight cooling, but a trend line showing all the intermediate readings shows clear evidence of warming. Or the report may claim that an effect limited to one area can be generalized to a whole continent. Or they may simply be reporting the variations caused by methodology errors as solid data to confirm their views.
So there's where my conclusion really comes from. Not the mere existence of a consensus that humans are causing our climate to change - that consensus seems pretty well confirmed to me, but as I said, science isn't majority-rule. No, the real convincer for me is how often, and how badly the opposition has to lie to try to create doubts in public opinion. If they really had facts on their side, they'd use them. Apparently, they don't.