You know, Jeff, for someone who believes so heavily in individual freedom and personal responsibility, you sure do a lot of broadly categorizing people and making blanket statements.
Implementing a "you're not allowed to post in this thread, unless you're a board-certified, licensed, and practicing expert on whatever's being discussed; or Jeff's going to call you names" policy doesn't sound like a very effective idea.
So what. We're a board full of average people, who all have feelings or hypotheses about things based on our personal experience. And so what if you disagree with what somebody says, or don't think they've got the science to back it up? Tell them that, but don't get sand in your vagina just because they're not an expert, so therefore, they need to STFU and GTFO.
In an unusual fit of something resembling maturity (I know, it surprises even me) I simply refuse to take a position one way or the other. I am *violently* apathetic about the issue, and since I'm not well-read in the subject I think that is the only reasonable position for me to take - I wish this was more frequent, because then climate change science could take place more easily and comfortably without bullshit from the peanut gallery popping in only because of motives that aren't even remotely scientific.
The science of climate behavior has become a far stickier place to be for *both* sides of the debate, and everyone from corporate think tanks with environment-killing agendas to signwavers on the street to political commentators to Al Gore is doing damage to one of the few human endeavors that is actually capable of producing real progress. If people can't leave their coat, hat, ego, and politics at the door when discussing science, it's very hard for the discussion to achieve anything that isn't cockwaving cuntstuffery.
But, honestly, the bigger reason I support what I do (energy conservation, cutting down on burning fossil fuels, etc.) are things that have a lot more evidence to support them, like acid rain and high mercury levels in sea/wild life. Living in the shadow of the Adirondacks, you can go all over the place and find evidence of acid rain and, hell, all you need is a DEC fishing guide to see what it's done to the wildlife (apparently I'm not supposed to eat more that two lake trout a month, or I'm going to be retarded by the time I'm 30?). Localized air pollution, noise pollution, ground water pollution; the list goes on.