Monday, June 05, 2006

Truths, Convenient and Otherwise

Sorry about the gap there. I suppose a week and a half isn't all that interminable a lag in the grand scheme of things, but the point of blogging is to keep up, post something every day, blah blah blah. After a month of non-stop school and work, though, I needed a week of doing nothing. Anyway, nobody really complained that I wasn't blogging, which is...probably...a bad...sign.

So, yeah, that Al Gore movie. Go see it. It's not as overtly political, extremist, or unbalanced as one might expect (and by "one" I mean "I"). It's pretty straightforward without being boring, and it has a handful of really breathtaking images--or rather, pairs of images (then and now pictures of glaciers of the world, and the breakup of the Larsen B ice shelf, e.g.). If you're not convinced yet, it also functions as a movie-length ad for Mac laptops. Just throwing that out there for any interested readers.

You read this blog so you know that climate and weather, being one of those systems that is subject to incredibly small variances in temperature, pressure, cow flatulence, cosmic rays and muons from space, solar flares, and so on, is an agglomeration about which it is impossible to make discrete inferences. You simply cannot say that storm 'X' or drought 'Y' was caused by Global Warming (actually, you read this blog so you know that it's my contention that you can't even make inferences about discrete coin flips. So, you know, whatever). This was, for me, the strength of this movie--it looks at the very long, continuous, much more inference-able view.

Over the course of the last several million years the earth has gone through a relatively predictable course of ice ages and subsequent warmings. It's only in the last 50 years or so that we started measuring atmospheric CO2 levels, such that fifty (and thirty, and twenty) years ago, the popular scientific view was that we were headed back into another ice age. Then came weather balloon studies, and then they started drilling cores in the polar ice caps and doing some detective work. What they discovered was that there seemed to be a very clear historical connection between CO2 levels in the air and mean atmospheric temperature of the earth. This is the first graph presented in the movie and it's an incredibly powerful metric, showing both what carbon dioxide levels have been doing over the past 650,000 years and what they've been doing in the last fifty. Gore points at the height at the last ice age and follows it to where we are now and says, "The spread of this graph is, in the city of Chicago, the difference between a very nice day and having a mile of ice over your head."

Where we are now is in one of the temperate periods--the difference this time is that instead of heading back down into the next ice age, as we did all the times before, both CO2 levels and temperatures are heading upwards ever faster. And where we are now, as it turns out, is also this odd little quirk of the Earth's history. As has been pointed out many places, the human species has had the brain capacity it has now for the past 50,000-odd years, but it's only in the last 5,000 or so that civilizations arose. It's Odds Are One for the history of humanity--it happened to be that big-brained homo-sapiens landed in a climate where you could stop hunting and gathering and start farming and domesticating (other people are just calling that "luck" these days, but I hear that if you invent a hermeneutic principle that describes the same thing using bigger words, people will give you a book contract). Having gotten to this point, and seemingly having a vested interest in, you know, sticking around, it seems that not only do we not want it to get markedly warmer, we kind of need to maintain the same conditions that we've grown up in. That ice age we might otherwise head into isn't going to be much fun either. If by some miracle we actually don't heat the earth up beyond its carrying capacity, our next problem will be figuring out long term climatological geostasis. Well, not your or my problem. But somebody's problem.

Next: Knee-jerk critiques of more texts!
Tags: ,

No comments: