I have spent the last few days reworking a series of short essays intended as a kind of post-script to a novel I have just about completed. The following is one of those essays. I have covered much of the same ground in this blog before, though with a slightly different focus, but I want to try out this piece and see how it reads. Feel free to comment with any feedback.
The Post-Petroleum World
Ecological Memory depicts a world of both ox-carts and robotic exoskeletons. Some readers might ask why. Yes, this is a world without fossil fuel, but it’s clearly a technologically advanced society, so why are they stuck using ox-carts? Why not use renewable energy?
The short answer is that they can and do, but if they used enough renewable energy to fully replace fossil fuels, they’d just wreck the world again. Where energy comes from is less important than how much is used.
We’re used to telling the story of technological progress in terms of innovation; cars are more advanced than ox-carts, so they go faster. But the other side of the same story is energy. A car than ran on just a few bales of hay couldn’t go much faster than an ox, no matter how advanced it was. Greater technology has allowed us to use more and more energy and that, not innovation alone, gives us our unprecedented power.
Fossil fuel made possible our energy increases. Fossil fuel use has also caused climate change and ocean acidification, and it indirectly causes several other ills, such as biodiversity loss. The mechanisms involved should be roughly familiar to most readers. The surprise is that drawing the same amount of energy from some other source would likely cause similar problems. Only the mechanisms would be different. To understand why, we need to take a dive into complex systems science.
“Complex,” here, has a specific, technical meaning. A system is complex if it has certain properties, such as self-organization and “nestedness,” meaning a system can have smaller complex systems inside it. I am a complex system and so are you. So are cells, ecosystems, and biospheres, among other examples. Whole books have been written on these systems, and those books are worth a read, but the important thing to know is that systems science is all about the flow of energy.
Complex systems can fight entropy and win. Entropy, readers may remember, is the tendency for everything to gradually run down as energy dissipates. Complex systems also lose energy to dissipation, but they don’t run down because they can actively draw more energy in from outside. If a system is drawing in more energy than it loses, it is anti-entropic. Think of a baby, eating and eating, and turning all those calories to growth and development, or a young forest, rapidly increasing in both biomass and biodiversity. Eventually, the system reaches a point of equilibrium where energy inputs equal losses, and growth stops. That’s maturity. From the standpoint of systems science, individual humans remain mature very briefly. Almost as soon as we reach full size, our metabolisms slow and we start losing energy, what’s called the entropic phase. More colloquially, it’s called aging. If something speeds up the entropy, or causes entropy before maturity, that’s illness or injury. A system that stays entropic long enough will cease being complex. That’s death.
All complex systems go through these phases, though not all automatically become entropic at a certain age. Forests, for example, don’t get old. They can become entropic, though. A forest on fire is entropic, for example. If the fire isn’t too severe, the forest will survive and become anti-entropic again for a while as it re-grows. As Andy explains in the story, size, complexity, and stability increase and decrease together. Adults aren’t just bigger than babies, they are also smarter and more resistant to disease. And there’s a reason we sometimes call the latter part of our entropic phase the second childhood.
All this energy has to come from somewhere, and complex systems often draw energy from the larger systems they are nested within. My cells draw energy from me. I draw energy from my society (mostly by working for a living), and my society draws energy from the biosphere. The catch is that if the smaller system draws too much energy, it will force the larger system into the entropic phase.
Think about why cancer kills if it isn’t successfully treated. Think about a forest being logged at an unsustainable rate. Think about the rapid burning of fossil fuel.
The biosphere, too, is a complex system, and it, too, had an anti-entropic phase when it was actively growing and becoming more complex and more stable—we know it was growing because the carbon dioxide concentration in the air was falling. Remember that plants store solar energy in carbon compounds built out of carbon dioxide and water. Free, breathable oxygen is the byproduct. Those carbon compounds then become the biomas and energy source of the entire living world. As the biosphere grew, the supply of carbon in the atmosphere shrank. The carbon dioxide/oxygen ratio eventually stabilized as the biosphere entered maturity. In recent decades, the carbon concentration has been rising again as the Earth entered an entropic phase.
Let me repeat that; the biosphere is currently entropic because of us.
The loss of stability and complexity and size always go with the loss of mass and energy as a complex system starts to die. Erratic weather, a changing climate, and widespread biodiversity loss are simply what these familiar symptoms look like on a large scale.
That burning fossil fuel should trigger an entropic phase isn’t surprising, given that the whole point of fossil fuel use is to access a lot of energy. The biosphere provides us with an annual energy budget of less than the total solar energy we receive, solar energy that builds plant tissue, drives winds, and moves waters. Were we to stay within that energy budget, living on sustainable forestry and agriculture, plus wind, water, and solar, most of the power we take for granted today would simply be out of our reach. Fossil fuel makes it all possible, and does so by giving us energy at a higher rate than what the biosphere actually receives. Biospheric entropy is the inevitable result.
To be clear, if we stop using so much energy, the biosphere will re-enter an anti-entropic phase and recover, though it will take a very long time for full recovery, possibly millions of years. There is hope, though time is getting short.
Giving up fossil fuel entirely is probably a necessary step towards sustainability. What’s the alternative, some complicated global carbon rationing system? Who could administer such a thing? But the end of the Age of Oil alone will not protect us. Should we ever find and use an alternative energy source to again draw more energy from the biosphere than the biosphere actually has to spare, we’ll be back in the same entropic muddle we’re in now. It would be like replacing a cancerous tumor with a six-mile-long tape-worm. The patient would still die, the only difference would be the mechanism.
Energy is energy. Using too much has consequences.
We will return to an energy budget similar to what the world had prior to the Industrial Revolution. One way or another, we will have to. And that change will impose real limitations on what we can do and how we can do it.
But an energy budget is not a time machine. We will not lose the scientific and cultural advances we have made, nor will we cease advancing. We won’t return to pre-Industrial Revolution life. We will build something new. What that something might be, I can’t say. Exoskeletons and oxcarts are simply part of my guess as to one possibility.