Plenty
of books in the 1970s and early 1980s applied the lessons of ecology to
the future of industrial civilization and picked up at least part of
the bad news that results. Overshoot was arguably the best of the
lot, but it was pretty much guaranteed to land even deeper in the
memory hole than the others. The difficulty was that [William R.] Catton’s book
didn’t pander to the standard mythologies that still beset any attempt
to make sense of the predicament we’ve made for ourselves; [...] he explained how
industrial civilization was cutting its own throat, how far past the
point of no return we’d already gone, and what had to be done in order
to salvage anything from the approaching wreck.
The core of Overshoot, which
is also the core of the entire world of appropriate technology and
green alternatives that got shot through the head and shoved into an
unmarked grave in the Reagan years, is the recognition that the
principles of ecology apply to industrial society just as much as they
do to other communities of living things. It’s odd, all things
considered, that this is such a controversial proposal. [...] human societies
are as subject to the laws of ecology as they are to every other
dimension of natural law.
Let’s
start with the basics. Every ecosystem, in thermodynamic terms, is a
process by which relatively concentrated energy is dispersed into
diffuse background heat. Here on Earth, at least, the concentrated
energy mostly comes from the Sun, in the form of solar radiation—there
are a few ecosystems, in deep oceans and underground, that get their
energy from chemical reactions driven by the Earth’s internal heat
instead. Ilya Prigogine showed some decades back that the flow of energy
through a system of this sort tends to increase the complexity of the
system; Jeremy England, a MIT physicist, has recently shown that the
same process accounts neatly for the origin of life itself. The steady
flow of energy from source to sink is the foundation on which everything
else rests. The
complexity of the system, in turn, is limited by the rate at which
energy flows through the system, and this in turn depends on the
difference in concentration between the energy that enters the system,
on the one hand, and the background into which waste heat diffuses when
it leaves the system, on the other.
Simple
as it is, it’s a point that an astonishing number of people—including
some who are scientifically literate—routinely miss. [...] one of the core reasons you can’t power a
modern industrial civilization on solar energy is that sunlight is
relatively diffuse as an energy source, compared to the extremely
concentrated energy we get from fossil fuels. [...] Nature
has done astonishing things with that very modest difference in
concentration. People who insist that photosynthesis is horribly
inefficient, and of course we can improve its efficiency, are missing a
crucial point: something like half the energy that reaches the leaves of
a green plant from the Sun is put to work lifting water up from the
roots by an ingenious form of evaporative pumping [...] all told, a green plant
is probably about as efficient in its total use of solar energy as the
laws of thermodynamics will permit.
That
said, there are hard upper limits to the complexity of the ecosystem
that these intricate processes can support. You can see that clearly
enough by comparing a tropical rain forest to a polar tundra. The two
environments may have approximately equal amounts of precipitation over
the course of a year; they may have an equally rich or poor supply of
nutrients in the soil; even so, the tropical rain forest can easily
support fifteen or twenty thousand species of plants and animals, and
the tundra will be lucky to support a few hundred. Why? The same reason
Mercury is warmer than Neptune: the rate at which photons from the sun
arrive in each place per square meter of surface.
Near
the equator, the sun’s rays fall almost vertically. Close to the
poles, since the Earth is round, the Sun’s rays come in at a sharp
angle, and thus are spread out over more surface area. The ambient
temperature’s quite a bit warmer in the rain forest than it is on the
tundra, but because the vast heat engine we call the atmosphere pumps
heat from the equator to the poles, the difference in ambient
temperature is not as great as the difference in solar input per cubic
meter. Thus ecosystems near the equator have a greater difference in
energy concentration between input and output than those near the poles,
and the complexity of the two systems varies accordingly.
All
this should be common knowledge. Of course it isn’t, because the
industrial world’s notions of education consistently ignore what William
Catton called “the processes that matter”—that is, the fundamental laws
of ecology that frame our existence on this planet—and approach a great
many of those subjects that do make it into the curriculum in ways that
encourage the most embarrassing sort of ignorance about the natural
processes that keep us all alive.
A
human society is an ecosystem. Like any other ecosystem, it depends
for its existence on flows of energy, and as with any other ecosystem,
the upper limit on its complexity depends ultimately on the difference
in concentration between the energy that enters it and the background
into which its waste heat disperses. (This last point is a corollary of
White’s Law, one of the fundamental principles of human ecology, which
holds that a society’s economic development is directly proportional to
its consumption of energy per capita.) Until the beginning of the
industrial revolution, that upper limit was not much higher than the
upper limit of complexity in other ecosystems, since human ecosystems
drew most of their energy from the same source as nonhuman ones:
sunlight falling on green plants.
The
discoveries that made it possible to turn fossil fuels into mechanical
energy transformed that equation completely. The geological processes
that stockpiled half a billion years of sunlight into coal, oil, and
natural gas boosted the concentration of the energy inputs available to
industrial societies by an almost unimaginable factor, without warming
the ambient temperature of the planet more than a few degrees, and the
huge differentials in energy concentration that resulted drove an
equally unimaginable increase in complexity. Choose any measure of
complexity you wish—number of discrete occupational categories, average
number of human beings involved in the production, distribution, and
consumption of any given good or service, or what have you—and in the
wake of the industrial revolution, it soared right off the charts.
Thermodynamically, that’s exactly what you’d expect.
The
difference in energy concentration between input and output, it bears
repeating, defines the upper limit of complexity. Other variables
determine whether or not the system in question will achieve that upper
limit. In the ecosystems we call human societies, knowledge is one of
those other variables. If you have a highly concentrated energy source
and don’t yet know how to use it efficiently, your society isn’t going
to become as complex as it otherwise could. Over the three centuries of
industrialization, as a result, the production of useful knowledge was a
winning strategy, since it allowed industrial societies to rise
steadily toward the upper limit of complexity defined by the
concentration differential. The limit was never reached—the law of
diminishing returns saw to that—and so, inevitably, industrial societies
ended up believing that knowledge all by itself was capable of
increasing the complexity of the human ecosystem. Since there’s no upper
limit to knowledge, in turn, that belief system drove what Catton
called the cornucopian myth, the delusion that there would always be
enough resources if only the stock of knowledge increased quickly
enough.
That
belief only seemed to work, though, as long as the concentration
differential between energy inputs and the background remained very
high. Once easily accessible fossil fuels started to become scarce, and
more and more energy and other resources had to be invested in the
extraction of what remained, problems started to crop up. Tar sands and
oil shales in their natural form are not as concentrated an energy
source as light sweet crude—once they’re refined, sure, the differences
are minimal, but a whole system analysis of energy concentration has to
start at the moment each energy source enters the system. Take a cubic
yard of tar sand fresh from the pit mine, with the sand still in it, or a
cubic yard of oil shale with the oil still trapped in the rock, and
you’ve simply got less energy per unit volume than you do if you’ve got a
cubic yard of light sweet crude fresh from the well, or even a cubic
yard of good permeable sandstone with light sweet crude oozing out of
every pore.
It’s
an article of faith in contemporary culture that such differences don’t
matter, but that’s just another aspect of our cornucopian myth. The
energy needed to get the sand out of the tar sands or the oil out of the
shale oil has to come from somewhere, and that energy, in turn, is not
available for other uses. The result, however you slice it conceptually,
is that the upper limit of complexity begins moving down. That sounds
abstract, but it adds up to a great deal of very concrete misery,
because as already noted, the complexity of a society determines such
things as the number of different occupational specialties it can
support, the number of employees who are involved in the production and
distribution of a given good or service, and so on. There’s a useful
phrase for a sustained contraction in the usual measures of complexity
in a human ecosystem: “economic depression.”
The
economic troubles that are shaking the industrial world more and more
often these days, in other words, are symptoms of a disastrous mismatch
between the level of complexity that our remaining concentration
differential can support, and the level of complexity that our preferred
ideologies insist we ought to have. As those two things collide,
there’s no question which of them is going to win. Adding to our total
stock of knowledge won’t change that result, since knowledge is a
necessary condition for economic expansion but not a sufficient one: if
the upper limit of complexity set by the laws of thermodynamics drops
below the level that your knowledge base would otherwise support,
further additions to the knowledge base simply mean that there will be a
growing number of things that people know how to do in theory, but that
nobody has the resources to do in practice.
Knowledge,
in other words, is not a magic wand, a surrogate messiah, or a source
of miracles. It can open the way to exploiting energy more efficiently
than otherwise, and it can figure out how to use energy resources that
were not previously being used at all, but it can’t conjure energy out
of thin air. Even if the energy resources are there, for that matter, if
other factors prevent them from being used, the knowledge of how they
might be used offers no consolation—quite the contrary.
That
latter point, I think, sums up the tragedy of William Catton’s career.
He knew, and could explain with great clarity, why industrialism would
bring about its own downfall, and what could be done to salvage
something from its wreck. That knowledge, however, was not enough to
make things happen; only a few people ever listened, most of them
promptly plugged their ears and started chanting “La, la, la, I can’t
hear you” once Reagan made that fashionable, and the actions that might
have spared all of us a vast amount of misery never happened. --
John Michael Greerref