Thursday, October 7, 2010

sustainability, part 2

I want to clarify the post I wrote on sustainability yesterday. There are many definitions of the word "sustainability", and I don't want to give the impression that I'm impugning environmentalism. I'm not. In some contexts, it's a feel-good buzz-word with little substance, but that's not the case for all uses of the word.

One important, legitimate use of the concept has to do with promoting sustainable development: "development that meets the needs of the present without compromising the ability of future generations to meet their own needs." (link) Of course this encompasses a lot, and different organizations and institutions have approached the subject differently. In general what it points to is the need to reconcile social and economic demands with environmental ones. How do we increase human affluence while at the same time dealing with the pressures placed on the environment by population growth, energy use, greenhouse gas emissions, soil erosion and depletion, species extinction through deforestation and over-fishing, pollution of fresh water sources, etc.?

These aren't marginal questions. On the contrary, I believe they're the problems demanding the most immediate attention right now. Many of them might be soluble, and their solutions are connected on a deep level with issues of human justice. More on that in a bit.

But there's another definition of "sustainable" I was using in my last post which is separate from but connected with the sense intended by environmentalists. That has more generally to do with how biological systems remain diverse and productive over time. It's separate from the environmentalist conception of sustainability in the sense that it's more general, and it does not necessarily imply human decision-making. An ecosystem in this sense might be sustainable or unsustainable in the absence of humans. For example, if you have a closed system in which organism A is the natural predator of organism B, the system (relationship between the two organisms) is unsustainable if A can completely kill off B in a generation or two before B can replenish itself through reproduction. So they're separate concepts.

But the two concepts come into relation when we think about the specific impact human civilization has on the environment. And they're certainly in relation—I would say confused with one another—when someone claims that modern human civilization is the original and sole source of unsustainability in the larger, ecological sense. It was against this latter claim which I was trying to intervene.

Yes, modern civilization as it currently exists is not sustainable. If development continues in a straight line from where it is now, our civilization will in all likelihood collapse.

But it's also true that every civilization which has ever existed—and almost every form of human society above the hunter-gatherer level—was also unsustainable. In some cases it was for internal, economic and political reasons; in many cases it was for ecological reasons. Jared Diamond goes through these examples in detail in his book Collapse.

But what few people appreciate is that some hunter-gatherer societies were also unsustainable in both senses of the word. They wreaked ecological havoc, and their form of development led to their demise. The Clovis culture of North America serves as an example. So do the first inhabitants of Australia. Human life itself appears to become unsustainable in many cases, even in the absence of capitalism and modern industry.

Now, unsustainability does not entail annihilation. I think almost anyone would agree that Roman civilization was unsustainable. It did, after all, collapse! Whether that was for ecological reasons or not isn't important here. What matters is that the techniques of production developed by the Romans were not completely lost. In fact, many of them survived and were developed down through the Middle Ages by European Christians and by Muslims in the Near East. Sometimes techniques are totally lost, like writing when the Mayan civilization collapsed. But it's not as though the collapse of the Roman Empire threw Eurasia back into the stone age. We might say the Roman Empire as a particular kind of human civilization was unsustainable, even while in a more general sense we can say that human civilization itself, as a genus, has sustained itself and continued to develop.

This brings us to the question of the sustainability of life itself. Here we have to deal with the broad, ecological category of sustainability. Does life remain diverse and productive over time?

I would say it depends on the time scale you look at, and it depends when in the history of time you're looking. If you're looking after the Cambrian explosion, and you're looking at a time-slice of a few tens of millions of years, then yes, you're liable to find sustainability. But if you take the Phanerozoic (the last 540 million years) as a whole, the picture looks quite different:

This is a graph of biodiversity since the Cambrian explosion. (The Cambrian explosion marks a radical proliferation of life. It's when modern body plans came into existence.) The yellow triangles on the chart represent the major mass extinctions. They're known as the "big five" because there are five of them: (1) the Ordovician-Silurian event (27% of all families and 57% of all genera wiped out), (2) late Devonian extinction (19% of all families, 50% of all genera and 70% of all species, gone), (3) the Permian-Triassic extinction (mother of all extinction events in which 53% of marine families, 84% of marine genera, about 96% of all marine species and an estimated 70% of land species are wiped out), (4) Triassic-Jurassic extinction event (20% of marine families and 55% of marine genera went extinct), and (5) the Cretaceous-Tertiary (K-T) extinction event (this is the one that killed the dinosaurs, but it took 70% of all species with it, too).

The best known of all these is of course the last one, the extinction of the dinosaurs. That's also the one paleontologists are almost certain was caused by an outside event, the collision with the earth of a 15 km wide asteroid. This is probably why many people have been led to believe that extinction events are caused by the intervention of things like comets or volcanos. But there's hardly any consensus as to what caused these extinctions, or the five other minor extinctions (blue triangles on the chart). Is this a case of the smooth, sustainable evolution of life being interrupted by chance bollide impacts or volcano eruptions? Or does life bring these mass extinctions upon itself when it develops too far in a direction which is unsustainable?

The point comes home more emphatically when we switch time-scale. Let's pull back and think about the period before the Cambrian explosion, what used to be called the "Precambrian" period but is now called the Archean and the Proterozoic. Now we're thinking about life on the order of billions or hundreds of millions of years, not tens of millions of years. If we imagine the Earth were only 12 hours old, we would be talking about what happened between about 2:00 (about when life started) and 10:00 (a little after animals came about).

Now we start to notice some drastic events. Starting around 3500 ma, photosynthesis starts. The cyanobacteria in the world's oceans are converting sunlight and CO2 into food, and they're releasing oxygen into the oceans. First the oxygen is absorbed by the water and the rocks in the oceans. After a few hundred million years of that, the oceans become saturated, and the oxygen starts to fill the atmosphere. The theory accepted by the scientific community is that the oxygen oxidized the methane in the atmosphere. The methane could no longer act as a greenhouse gas. So the earth froze. And not just a little bit. The whole thing froze. It may have been the greatest mass extinction in the whole history of life. Even before the drastic increase of oxygen in the atmosphere, the oxygen in the world's oceans would have been toxic to the anaerobic lifeforms that lived there. Whatever managed to survive the first catastrophe was probably wiped out by the second.

So there's widespread scientific consensus that at least once, life went in a direction which was unsustainable, i.e., which created instability and which decreased diversity.

I didn't realize this when I wrote the post yesterday, but there's a book that just came out on this subject by Peter Ward.  Ward also has a TED talk, but it's a bit scattered at the end, in my opinion.

I think there's a lot of evidence in favor of Ward's position. On the long-term scale, we have at least one drastic ecological catastrophe caused by life itself. On the short-term scale (last 540 ma) we have 10 extinction events (5 of them major), and while some of them were caused by outside events, it's unlikely all of them were. It really seems as though life has a tendency to fuck itself over (I'm not using "fuck" here in a technical sense, by the way).

I think there are a few implications of this:
  1. Intelligent design just has to be wrong. Imagine you're an intelligent designer—presumably omniscient and omnipotent and, above all, Good—and you set yourself the task of creating intelligent beings by means of a purely causal process (because for some reason, even though you're omnipotent, you can't just snap your fingers and create them). Not only do you design a system in which 99.9% of all species which ever existed go extinct (to say NOTHING of the individuals who have feelings, personal goals, whatever). You design it so the system is actually suicidal in many, many circumstances. (Imagine that if you ran the experiment a million times, most of the time it would kill itself completely and produce nothing.  We don't yet have other planets to compare ours to, but maybe this is what happens.)  There's no design in this system! Even a person with below-average intelligence could do better.
  2. The likelihood of life evolving from prokaryotes and archaea to eukaryotes and beyond is probably low. It seems if you get above a certain threshold (perhaps represented by the Cambrian explosion), suicide attempts on the part of life are still frequent, but they're less effective. (Assuming the worst mass extinctions were pre-Cambrian.) This might be why so much of the history of life on earth is represented by such simple organisms. It takes a LOT of trial and error to cross that threshold. Once one does, the evolution of complex bodies and sentience might be relatively meteoric (if still highly problematic). But between exoteric catastrophes and suicide attempts by life, it may be hard to cross that line.  So most attempts at sentient beings fail.
  3. If (2) is right, that might explain why we don't see signs of intelligence in the universe. Ward makes just this case in an earlier book. Another possible explanation is that superintelligent civilization is out there, but it has no interaction with electromagnetic radiation (they don't emit it, and they don't use it for energy). That's possible, but then so is anything. Going by available evidence, I'm betting the first life we encounter looks like this and not like this.
  4. From a certain abstract point of view, there's nothing novel about the fact that our way of life is unsustainable. Life may never have been sustainable for very long periods of time. And yet it's evident that life continues. Despite all these catastrophes, life came into existence only once on earth. The experiment has been interrupted many times by ecological catastrophe, but it has continued.
Of course the problem with this last point is that it's true only in a very abstract sense. Sure, cyanobacteria had the power to change the entire ecosystem of the earth and did. But it took them about a billion years to do it. That's roughly the amount of time that elapsed between the invention of the technique of photosynthesis and the first snowball earth. Never before has there existed a force on earth capable of bringing out such widespread catastrophe on the order of centuries. Our technology and our intelligence have collapsed the geological time scale down to the human time scale. We don't only reap the rewards of progress exponentially. We reap the dangers that way, too.

No doubt plenty of people think "So what? Once humans are gone, life will continue without us. There's nothing we can do to the ecosystem worse than what previous forms of life have done.  Maybe it's better to revert back to simple organisms."

Our survival instinct militates against this, of course. But I think there's a good reason to reject fatalism.

For the first time in the history of life—maybe in the history of the universe—someone cares about individuals. God doesn't care about individuals. If He did, he wouldn't have sacrificed 99.9999999% of them in the process of evolution. The process of evolution cares nothing for individuals. All it selects are genes. (As William James pointed out long ago to Herbert Spencer, evolution is survival of the fittest species, not the fittest individual.) I think one could argue about how much even previous human civilizations have cared about individuals compared with this one.

We have an almost endless list of ecological, economic, and social justice problems. Two billion people on our planet still struggle to put shoes on their feet and food in their stomachs. A woman in the United States has to worry about whether or not she'll be assaulted while walking down the street for no other reason than that she was born a woman. We wipe out thousands of species each year. We're a disgusting mess—just like you would expect from any form of life—just more nuanced and satisfied with ourselves over it. It could make one beg for plague or bollide.

But if you extricate yourself and think about it—not optimistically, not pessimistically, but just abstractly and rationally—our suffering is a sublime achievement of the universe. We feel injustice done at the expense of the dignity of the individual. It hurts the body, and it hurts the capacity to reason.

If we leave the universe, there will be no one to champion the rights of the individual. There will be no justice. Certain species will endure, and others will be wiped out. Nothing but the pure mechanism of action and reaction will exist. There will be no justice. Nor will there be pity or forgiveness. There is no God, if by that we mean a rational, moral author of the world. Before us there was no concern with the individual or with purpose, and if we die, they will die with us.

By a (probably) rare stroke of luck, evolution has brought us to this point where we can, at least in one sense, negate the process of evolution. Evolution has valorized the genus over the individual. Maybe we can reverse that. The possibilities are too tantalizing and the implications are too spectacular not to try.

Anyway, I said I would mention something about the relationship between ecology and social justice, and that we might have the capacity to resolve our sustainability problems. Check this out. It's a talk by Hans Rosling on population growth. (I posted something by him before.) You should watch the whole thing. He's one of my favorite TED speakers, and his animated graphs are awesome (though in this one he goes low-tech). Choice quote:
Child survival is the new green. Only by child survival will we stop population growth. But will it happen? I'm not an optimist. Neither am I a pessimist. I'm a very serious possibilist. It's a new category. Where we take emotion apart and we work analytically with the world. It can be done. We can have a much more just world. With green technology and investments to end poverty and global governance, the world can become like this.
I want to return to this topic, but I'm exhausted from writing tonight (2 hours straight now—I wonder if anyone reads this stuff). I think we live during an amazing time during which absolutely unprecedented events are occurring. Some might read the narrative of technological advance as something which makes human freedom obsolete. But on the contrary. If I'm right in what I've said in this post, than individual human choice is more important and more powerful than ever. It's the ultimate test of human reason to see if we can make it through the current impasse. For those who are ambitious and creative, it's the best time to be alive.

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