I'm skeptical about all predictions of disaster. I'm predictably skeptical about doom-and-gloom predictions used to rationalize big expansions of government power: global warming, overpopulation, avian flu, resource depletion, terrorism, nuclear proliferation, "Mexifornia," etc. But I've also long raised my eyebrow when libertarians predicted a Clintonian coup, hyper-inflation, or an American re-run of the Weimar republic.
There's not enough time in the day for me to know enough about all of these disasters to doubt them on their specific merits. But I do it anyway. How do I justify it?
The superficial reason is that people are trying to get attention, which leads to a "race to the scariest story." That's true, but it hardly seems strong enough to justify my blanket skepticism. The fact that people exaggerate hardly proves that the end is not nigh.
My deep reason is simpler: The fact that we've gotten as far as we have shows that true disaster must be extremely rare. Unless fears almost always failed to materialize, we'd already be back in the Stone Age, or plain extinct. It's overwhelmingly unlikely that we've gotten lucky a million times in a row. Thus, unlike my co-blogger, I think there is a good reason to expect global warming models to be milder than models predict. Namely: As a rule, disasters are milder than predicted.
Now you could say: "That was then, this is now." Maybe modern conditions are so different that you can't generalize from the past. All I can say here is that social conditions have radically changed many, many times, and we're still here. We've gone from hunting and gathering to agriculture to industrialism to the information age. We've gone from tribalism to city-states to monarchy to democracy. Each step of the way, someone could have semi-plausibly denied that the past remained a useful guide to the future. And each step of the way, they've been wrong.
Dickens wrote wisely: The more things change, the more they remain the same. Problems come and go, but smart money says that things are going to work out.