Yesterday, I had lunch with my very good friend Bill Case. Bill and I have been meeting for lunch once a week for many years. Overtime, we’ve constrained ourselves to a select few places, comfortable places. Really and truly, it’s pretty much narrowed down to The Main Street Cafe in downtown Madison, where the food is always excellent and, perhaps even more importantly, they know us very well. And forgive us. When I say “know us very well”, I mean that when one of us arrives, the waitress automatically brings precisely what both of us will be drinking (Bill has hot spiced tea in the winter, I always have unsweetened tea with extra lemon), and then proceeds to suggest the things they know we’ll like. And subtly warn against what they know we won’t. You know, “A place where everybody knows your name”. And what you eat. And when I say “forgive us”, well, Bill and I talk a lot during lunch. And we usually get loud, and very animated, and by the end of the meal, depending on the discussion, we might even approach going manic. Especially if the discussion happens to involve politics. Or the climate. Or almost anything, really.
We just get excited about the world and what’s happening in it, that’s all. And we kind of forget we’re, you know, in a public place. That’s probably why, when the weather permits, they’re glad we sit outside. The open air tends to absorb our enthusiasm.
So yesterday (which was fairly calm, more in the introspective vein than an End of Civilization rant), the topic turned to this blog. We were discussing my most recent post, which had concerned Newt Gingrich. This was a topic that could have easily careened off into one of those manic exchanges, but instead we talked about blogging in general. Bill was considering cranking up his own blog, but worried out loud about whether he’d have something worth blogging about frequently enough to warrant it, much less a daily commitment. “I’d probably end up writing something like, ‘Air is wonderful!’”
And there it was. Boom. Bill had supplied my whole thesis for today, launched my brain into that spin that it sometimes takes, and pretty much determined today’s entry in those three words. Because guess what? Air is wonderful.
It’s a miracle, really. Consider the air.
It’s a constant mixture, and has been for many millions of years. 78% nitrogen, 21% oxygen, almost 1% argon (how did that get in there?), about 3 hundredths of a percent the infamous CO2, traces of other gases, a bit of water vapor that averages about 1%. Although the fluctuations around that 1% H2O have a disproportionate effect on our day-to-day weather: rain or drought, feast or famine, all hinging on minute differences in the amount of water vapor. It was not always thus: when the planet first formed, there was no air at all. When it did form, that initial atmosphere would have been a toxic mix of methane and other carbon compounds, sulfuric and other acids. Gradually, atmosphere changed and water was introduced to the planet, most likely by virtue of a constant bombardment of those dirty ice balls we call comets. After billions of years, and with the introduction of living organisms, the air began a long evolutionary process, finally arriving, some 50-60 million years ago, at the ratios we have today. And since then, the ratio of gases has remained constant.
But it’s the nitrogen-oxygen ratio that represents the truly miraculous aspect of the atmosphere. We obviously require O2 to breathe. Every school child since Lavoisier has been taught that without the precious oxygen, air might as well be a vacuum for all the good it would do to keep us alive. In fact, your first thought might be, “If we need oxygen, why stop at 1/5 of the atmosphere? Why not 2/5, or half? Why not have all of the air be composed of oxygen?” I mean, if Michael Jackson slept in a hyperbaric oxygen tent, and pro football players suck O2 out of a tube to literally get their second wind, seems reasonable that the whole world would benefit if there was more oxygen floating around.
The fact is, we couldn’t live with that much O2. Oxygen is highly reactive. We breathe it, sure, but it’s also the thing that rusts metals and causes all kinds of deleterious chemical reactions. Oxygen oxidizes things. Breaks them down. Too much oxygen, the planet would actually be poisoned. And there’s another thing: If there were just a little higher concentration of O2 in the atmosphere, everything that could burn (wood, forests, petroleum, etc) would essentially be burning all the time. Remember the fire triangle? Fuel + Ignition + Oxygen? The fuel is all the plant life on the planet. Ignition is any stray lightning (there is lightning on our planet, somewhere, all the time). Pump up the oxygen content enough and the whole planet bursts into flames.
What keeps it from turning the place into a planet-wide funeral pyre? Nitrogen. Molecular Nitrogen (N2) is one of the least reactive substances you can imagine. It has what is called a triple bond between the two nitrogen atoms, a bond so strong that the molecule is almost inert (it’s not: but it takes a pretty hefty jolt to make it do something). So here’s this mixture of gases in the atmosphere. One of the most highly reactive, absolutely sine qua non for life substances, oxygen. A molecule that has the chemical “kick” that life absolutely requires. And then the big, totally insensitive, have to poke it with a stick to get its attention nitrogen, acting like a blanket to calm the oxygen down. The end result is that the O2 has just enough power to keep our life motors running, but not enough so that they scream out of control.
So. There has to be enough O2 to support life, but not enough to turn Earth into Dante’s Inferno. And here’s the real kicker, the eye-opener, the “what the hell?” piece of the puzzle. If the amount of oxygen increased by only a tiny percentage, the giant conflagration is inevitable. If it decreased by a tiny percentage, the air would be incapable of sustaining life, at least at the metabolic rates we’ve come to know and love. Meaning us. Humans.
Perhaps your first thought is: “Dang. How lucky that the O2 concentration just happens to be the magic number, 21%. And that the dullard molecular nitrogen makes up essentially all the rest.” Yes, lucky indeed.
Or is it? Several years ago, the British scientist James Lovelock noticed this happy coincidence. But he turned the question around. Is it luck that the atmosphere has this particular mixture, or is it inevitable? He proposed the Gaia Hypothesis to suggest it is the latter. According to his idea, the Earth acts in homeostatic fashion, self-regulating itself so as to maintain a sustainable equilibrium. This atmospheric composition is not an accident, it is a value that all life, working in concert with the physical substrate of the planet, arrives at so as to maintain that very life. The Earth is actively keeping everything within its purview in a state of dynamic equilibrium commensurate with life. And that goes for temperature, atmosphere, oceans, flora, fauna, all of it. In the extreme formulation of Gaia, the earth can be considered a single organism. And just as your body has a set of organs and sensors and systems that all work to maintain a nice 98.6 degrees and to stay healthy, so does the Earth. Fluctuations happen: we get sick, so does the Earth. But we return the steady state, and does she.
The Gaia Hypothesis is an idea that fundamentalists and conservatives tend to recoil from. The idea of an almost “aware” planet is too much. And of course even the word “Gaia” (the name of the primordial earth goddess in Greek mythology) sounds, well, too gay for that crowd. To be fair, Lovelock certainly never suggested that the Earth was “alive” or even aware in any sense that we would recognize. But it’s obvious that the idea strikes a resonant chord for all people and religions and philosophies that regard the world as a holistic entity. And no matter how one considers it, it remains a source of amazement that our atmosphere is so perfectly suited to our existence, when just a minor adjustment either way would have been so devastatingly different.
Yes, Bill, my friend, you’re absolutely right: Air iswonderful.
© 2012 Chuck Puckett