[Politics] Science is Opinion?

I'm not sure how we got to the point in society where scientific principles are something the lay person believes they can have an opinion on. You certainly didn't see this back in the big space exploration days, with Joe Shmoe decrying that crazy Buzz Aldrin and his "moon landing" story. Ok, admittedly there were a few people that denied the moon landing, but we generally called them paranoid schizophrenics or possibly crazy Uncle Steve.

The most obvious victim of this scientific normatism is global warming. It seems every week here lately I encounter someone that chortles whilst denying that global warming could possibly be real because it's been really cold this Winter. This generally causes me to reevaluate my relation with that person and decide whether I should lose my composure on them or if I should just smile, nod, then never speak to them again. The frequency of this conversation has caused me to ponder how this came about, and I've come up with a few reasons:

1. Science as Politics - The science of global warming has somehow ended up in the lions' cage of the American political arena, and as such people reason it must have bipartisan stances. "If Al Gore says it, and he was a Democrat, and I'm a Republican, then I must not agree" seems to be a logic I see applied; Nay Nay. The world is getting warmer, period. Whether we humans have a significant amount to do with that is the debate, not whether it's happening at all.
   
2. Everyone is an expert - I think there is a sense that because the weather is so observable and such a frequent topic of conversation people feel reasonably qualified to weigh in. "I can discuss the weather with my hair dresser and people I bump into in a diner." The leap is then made from feeling qualified to say "It's cold outside" to "The world is not getting warmer". This also stems from...
3. Myopic Viewpoint, a.k.a. "America is the World" - When people attempt to take what's happening "right now" as proof one way or the other, they generally only consider what's going on in America, at best. This precludes what's going in areas like Greenland, which is experiencing vastly different weather currently. The presence of global warming cannot possibly be rationally evaluated without a global viewpoint.
   
4. The Real 'Experts' are Idiots - The public views meteorology as inaccurate. Frankly, it is. People therefore presume "If these guys can't dial it in further out than a week, how can they possibly predict years into the future?" The error in logic here is that the study of global warming doesn't at all resemble that of weather prediction.Temperature trends are determined the same way trends are in almost every other field of study: take a set of past measurements (in this case temperatures) and project out where they will be based on trends over the past several years.This is a well vetted technique. In this particular case their are decades of data; it's pretty accurate.
5. Parsable vs. Observable Difference - The overall global temperature change that's being discussed is very minute. It's not something where your gonna step outside and notice that it's 5 degrees warmer every day this summer than last, and if you are seeing that, that's not global warming. The trend that's being discussed is statistical; it's small but will accumulate up over time such that in 50 years there will be an observable effect.