Incidentally, the above is why I (and many people, i think) am such a sucker for the rhetorical technique of "Yes, I _used_ to believe what you believe, and I was content with that, but then I discovered X and Y, and well, OK, that was uncomfortable but I rationalized _thus_, and then some guy over coffee shared with me argument Z, and boy _that_ was compelling, and..." This will almost always convince me more effectively than simply stating X, Y, and Z. This is dumb, I realize, but it works pretty reliably.
Some more ruminations.
One thing that puzzles me somewhat on this topic is the degree to which the argument loses sight of its practical goals.
I mean, it seems to me that the claim that matters for practical purposes -- the reason this is a political issue rather than an academic one -- is: "If we change our pattern of fossil fuel use in ways that reduce X and increase Y, we will change global climate conditions over the next N years in the following positive ways."
I find it rare that anyone discussing the underlying science remembers that that was the point. At best, they seem to be trying to prove "Our pattern of fossil fuel use over the last N years changed global climate conditions in the following negative ways."
And I get that the latter is an important step on the way to the former... but if you stop there, you get reactions like polyrhythmics. You also get a lot of knee-jerk environmentalism. "Global warming is our fault so we have to save the whales!" and that sort of thing.
So if you really want to weigh in on this usefully, I think you need to make the following points:
1) Global climate is significantly different today from what it was two hundred years ago, in the following ways: X, Y, Z.
2) Those changes are not just normal climate fluctuations, it's not solar permutations, it's not just one of those things that happens for reasons we don't understand. It's the result of our own actions, had we not done A, B, and C we would not be experiencing them.
3) Those changes are dangerous to humans. (People who talk about "destroying the environment" annoy me.)
4) Those dangers can be mitigated or eliminated by changing our behavior in various ways. If we do A', B', and C' and stop doing A, B, and C we will no longer suffer those dangers.
The evidence for 1) seems overwhelming and straightforward.
The evidence for 2) is not straightforward, and requires some care and intelligence to follow, but there sure is a lot of it.
The evidence for 3) seems pretty clear.
I'm remarkably uncertain about 4), myself.
And really, if 4) isn't true, then why should anyone outside of academia give a damn about 1-3?
[I'm just gonna say it. It's fun watching you have a conversation with yourself...] Can you expand out your ovjection to "destroying the environment"?
For that matter, I don't understand your fourth sentence. Isn't history important even to non-historians?
Oh, just wait 'till I start disagreeing with me and calling me nasty names.
Then the fun _really_ starts.
(Why yes, I _am_ bored today. How did you know?)
Re: "destroying the environment"
Objecting to "destroying the environment" makes one sound vaguely altruistic... like we're preserving a national monument or something.
Which just ain't so.
We can't destroy the environment any more than we can destroy the universe... at the end of the day there will still be an environment. The flap isn't about not "destroying the environment", it's about avoiding a lot of death and property damage... most relevantly to ourselves and property we'd sorta like to hold on to, like our houses and stuff.
Which is obvious, natch, but I hear people talk as if it weren't.
Re: history being important even to non-historians (which one is my fourth sentence again?)... typically, it isn't important in ways that have billions of dollars associated with them. I mean, sure, I'm vaguely interested in, say, how the asteroid belt formed. But I doubt I'll see much political discussion stemming from different theories about it.