The whole nut of the N&S view of the world is that their survey research has shown that human nature requires a lot of happy talk to muster the courage for positive reforms, and we should trust their scientific data on how humans react rather than our own intuition/political experience. So yeah, consider me unconvinced.Now, there's a good question about whether N&S are attacking a straw man (see Kate Sheppard's critique here), and I don't have a firm opinion about that. The apocalyptic strain certainly exists within the environmental movement, but I'm not plugged in enough to say for sure how widespread it is.
Instead, I just want to collect some opinions. N&S's critique may have hit home with me more than Ezra because the state of California happens to be blanketing the airwaves right now with a series of ads about global warming. Now, obviously, the "environmental movement" isn't responsible for these ads and shouldn't be blamed for them. Still, they're not untypical, and my reaction to them is that they make me want to slit my wrists every time I see one. I think they're exactly the kind of thing N&S are talking about.
So: help me set some kind of baseline for this stuff. Watch the ad and tell me what you think. Am I just having a weird, idiosyncratic response to it? Or is it really as depressing as I think it is? The full set of ads is here if you want to watch them all.