Well, I received quite a bit of feedback on my Overheated Conclusions post. In part I think folks misunderstood my point, which was largely about logic (thus the cutesy subtitle post hot, ergo propter hot). Consider the following syllogism:
1. The earth is getting warmer.
2. Any deleterious change in terrestrial conditions must be caused by human interference with the natural order.
Therefore human interference is causing global warming.
It's the second premise that I'm questioning (I have my doubts about the first premise, too, but I'm focusing on the second one right now). There is a kind of new-time religion here, which assumes a close connection between natural phenomena and human actions. Just as in olden days people thought that any famine, plague, earthquake, or other such occurrence was a sign of some deity's displeasure with humankind, so today many people consider climate change, species extinctions, and the like to be visitations inflicted upon humankind by Gaia for our many environmental sins. It's the same old wine in a brand new bottle.
Why do people believe that? Even if the climate is changing and species are dying off, how is the current bout qualitatively different from the climate changes and extinctions of old? Is there proof that we evil humans are causing these phenomena, or are we only assuming it because we accept the quasi-religious premise that any deleterious change in terrestrial conditions must be caused by human interference with the natural order?
Now, if you hold that premise, you attend to different things. Hurricanes, blizzards, droughts, heat waves, sudden storms, melting permafrost, shrinking glaciers, big icebergs, long growing seasons, clear waters in the arctic ice cap, and the like -- all of which have been occurring in natural cycles since time immemorial -- loom large in one's consciousness. They're all caused by us crafty humans and our evil environmental depradations. Yes, the sky is falling! Repent thine evil ways or Gaia will strike us down!
There are further premises here. One is that nature is a stable system that hardly ever changes, and then only gradually -- the gradualist thesis. The opposite thesis is catastrophism: that nature is far from predictable and that extreme changes sometimes happen in very short order without human meddling in the natural order. The classic examples of natural catastrophes are the asteroids that periodically rain down on our fragile little planet, wreaking massive climate change and extinctions. More modest catastophes include volcanic eruptions, earthquakes, and tsunamis (inexplicably, one of my interlocutors trotted out the recent tsunami in the Indian Ocean as evidence of human interference with nature!). The truth probably lies somewhere between extreme gradualism and extreme catastrophism (doesn't it always?); but it would be foolish to chalk every seemingly out-of-the-ordinary occurrence up to human interference with nature, since we know that geological and climatological changes were occurring long before humans arrived on the scene.
In a way, the Gaians overestimate the impact of us puny humans, and thus make us out to be more important than we are. Yes, the Gaians think, we are still the center of the universe because it's we who are causing these world-historical changes in the earth's climate! (Granted, we are evil, but still we are all-powerful.) Sorry, folks, but I have my doubts.
I admit that it's been several years since I've taken a good hard look at the scientific evidence in this area, and in my copious spare time I'll start to dip back into that. So I don't speak from authority -- I'm simply questioning authority (oh, perhaps that's not allowed anymore, eh?).
Finally, I wonder what those who worry about the falling sky are doing about the matter. I have a cousin who used to work assiduously to "minimize his footprint" (as he called it) by living in a hole in the ground (well, some kind of bermed house), growing his own food, etc. Very very few people are willing to go that far, and in my experience the most that people are willing to do is recycle some bottles and vote for public transportation (not ride it, mind you, just vote for it). Although I'm a global warming skeptic, I probably do more than 90% of the people in my heavily Green-Progressive-Democratic neighborhood to help "save the planet", for example by biking to work half the time and taking public transportation the other half (I have never seen anyone else from my neighborhood get on or off the bus at the same times I do during rush hour, and I see precious few people on the bike trail). I'm heavily in favor of nuclear power to wean us off fossil fuels. I'm heavily opposed to the agricultural subsidies that are destroying the Everglades and other natural areas. I think our current regime of flood insurance and government bailouts simply encourages people to build enormous houses in flood plains and coastal areas. I think urbanization is a good thing because it concentrates humans in limited areas and keeps them out of the wilderness. I don't subscribe to newspapers or magazines because I don't want to waste all that paper (and I call to cancel delivery of every catalog that arrives in the mail). I don't drive up to the mountains every weekend in my SUV (with the "Respect Your Mother" bumper sticker) to sit in stop-and-go traffic on the way to the ski slopes. Sure, I could do more, but I don't believe the sky is falling, either.
Yes, I'm sick of the hyprocrisy. Let those who preach lead the way in practicing.
End rant.