THE PROBLEMS WITH DEFINING SUSTAINABILITY
James P. Hamilton ©2012
The definition of sustainability that the Penn State Campus Sustainability Office uses is
as follows, "Sustainability is the simultaneous pursuit of economic well-being, human health and
prosperity, and environmental quality that balances the needs of present and future
generations." Many of the definitions of sustainability are something like this and therein lies the
problem.
What people are trying to do is to incorporate descriptions of the kinds of sustainability
into the definition itself and this muddies the waters. What virtually all definitions of
sustainability need is an adjective before the word “sustainability” so that the reader knows what
kind of sustainability is being defined. My personal definition does not try to deal with economic
well being or human health because they are a part of the TYPE of sustainability that is hoped
for rather than a definition of pure sustainability. So let me follow my own advice and use the
term “pure” to describe my own definition. I have written elsewhere about some general types of
sustainability which I called Easter Island Sustainability, Boom and Bust Sustainability,
Tyrannically Imposed Sustainability, and Humane Sustainability to name a few. By the way, the
above mentioned definition would fall generally under the heading Humane Sustainability,
though I no longer like that adjective much. So let me give you a sense of what I am now calling
Pure Sustainability.
First, let me establish some elements of the worldview from which this derives and then
move on to the specific underlying scientific assumptions upon which it is based. The main
worldview element is the belief that there is an objective reality out there to be discovered. I am
not saying that we can necessarily PERCEIVE it all of the time or accurately, but it is there. For
those who believe that the ONLY thing that matters is perception, I invite you to jump off a tall
building and flap your arms while believing, indeed perceiving, yourself to fly. I also would like
to point out that those who claim not to believe in an objective reality generally do not live their
lives in accordance with that belief. When told to go somewhere and do something, they act as if
the somewhere and the something are very real. If asked to put the paper in the desk drawer, they
do not stumble about in a confused state wondering if the desk and paper are real or not. They
put the real paper in the real desk drawer. But enough of that. I am not saying that perception is
not important, only that if it clashes with physical reality, it generally loses.
A second part of the worldview is that there are certain laws of the universe that we
cannot wish away and a few of these are critical to the understanding of and definition of pure
sustainability. The most important of these “laws” are E=mc2, and the first and second laws of
thermodynamics. Let’s start with Einstein’s famous equation.
The equation says that if we convert matter into energy, the amount of energy is equal to
the mass converted multiplied by the speed of light squared. Of course, the reason the amount of
energy produced in this conversion is so large is that the speed of light squared is a REALLY big
number. Witness the atomic bomb. Also implied in this equation is that matter and energy are
different forms of the same thing and are convertible from one form to another. Finally, the
reason we do not have nuclear matter-makers is because the speed of light squared is a REALLY
big number and the amount of energy we would need to make a tiny bit of matter would be
prohibitively large. This brings us to the first law of thermodynamics.
It is the ultimate conservation law. In lay terminology, it says that those interchangeable
items called matter and energy are neither created nor destroyed, they just are, that is they are
conserved. The most important things to get from this are that YOU CAN’T GET SOMETHING
FROM NOTHING! THERE ARE LIMITS TO WHAT IS! You cannot make either matter or
energy from thin nothingness. Energy can be changed from one form to another, sunlight
converted to stored solar energy in the form of plant sugars for example, but trees do not
magically appear out of nothingness. We live in what is, for all practical purposes, a finite Earth,
Moon, Sun system. Not having much access to the moon right now for material resources or
energy, we live in an Earth-Sun system that is FINITE…it has limits. There are those who argue
that the Sun provides us with an infinite amount of energy, but I fear they are misusing the term
infinite. To clarify how I am using it here, when I use the term infinite, I am referring to the size
or amount of something other than time. When I use the term perpetual, I am referring to time.
The Sun provides us with a FINITE amount of energy perpetually (again for all practical
purposes; I know the Sun will eventually wink out but not in a time frame that matters). The
second law of thermodynamics, which can be expressed in many ways, also plays a part in the
definitions of sustainability, but for this discussion nominally so. A physicist friend of mine once
succinctly said to me “The first law says you can’t win and the second law says you can’t even
break even.” As an aside, one definition of life I once heard was “It is the temporary ability for
an entity to overcome the second law of thermodynamics.” Kind of takes the romance and
mystery out of the term doesn’t it?
The upshot of all of the above rambling is to establish that fact that, regardless of
anyone’s perceptions to the contrary, we live on a finite planet in a finite system with finite
natural resources. All viable definitions of sustainability have to acknowledge that reality from
the start. What I am calling pure sustainability (hmmm, maybe the term biological sustainability
would be better) is simply a statement of what that reality means to any life form. The Sun
provides the energy to drive numerous cycles which allow us, as humans, to temporarily
overcome the second law of thermodynamics. The planet is the ultimate recycling machine and
unless we damage that machine sufficiently, it can provide a FINITE population of us with the
TEMPORARY use of natural resources and energy to sustain us in the short term individually
and in the long term as a species. And it can do it in perpetuity.
Whatever you define and however you define it, you are still ultimately stuck with the
objective reality. Economists can, for example, change the meaning of the word “resources’ to
mean something other than or in addition to natural resources, but they cannot make whatever
they are calling “resources” any less dependent on the laws of the universe for having changed
the definition. I have written elsewhere about the multiple paradoxes involved in trying to define
sustainability, even pure sustainability so I won’t go into it here. See my essay The Paradoxes of
Sustainability for more detail. However, let’s get back to the definition that began this essay.
It’s a perfectly reasonable definition of a hopeful KIND of sustainability. What it lacks is
an adjective placed before the word “sustainability” that both describes its kind and distinguishes
it from other kinds of sustainability, particularly pure, biological sustainability. What is
happening is that the word sustainability is being co-opted by all kinds of people and
organizations for all kinds of reasons and is losing its punch. Sustainable development was a
particularly early oxymoron of this ilk. We in the sustainability community need to attend to this
matter. The word can no longer stand alone. It must have modifiers to clarify how it is being
used in any particular context. But no matter what modifiers we use, no matter how we parse our
definitions, we can never allow the discussion to ignore the fact that there are some fundamental
laws of existence that place limits on what can and cannot be. There are many factors that impact
the kind of sustainability we might have, what it might look like, but E will still equal mc2 and
matter and energy will still be conserved.
In the other essay mentioned, I took a stab at an analogy to define pure sustainability (I
did not use the term “pure” in that essay). Let me briefly describe it here. If you look at the
Earth/Sun/Moon system as analogous to a bank and the economy, it works like this. The Earth
and its capacity to cyclically provide resources to use are like a bank in which there are some
large but finite money holdings. The resources (clean water, trees, soil etc.) that the Earth can
provide for us to use cyclically and in perpetuity are like the interest that you can extract from
the bank during any prescribed time. The Sun which provides the energy to power the various
cycles (hydrological, nitrogen, carbon, etc.) is like the economy with which the bank and its
holdings must interact to create interest. So, to define pure sustainability within the constraints of
the analogy, it is this, “ Living off the interest the bank provides while neither reducing the
principal nor damaging the bank’s capacity to create interest.” The fact that the economy (Sun),
bank (Earth and its cycles), and interest (extractable resources) are finite should be obvious by
now. There are lots of factors that have an impact on what that sustainability looks like as
regards justice, equality, morality and the like, but none of those factors can contradict the
realities of the laws of the universe. None of them can contradict the realities of PURE
sustainability. I have often said that, barring human extinction, we will ultimately live
sustainably; the only question is, what will it look like when we get there? The other definitions
try to answer that question as a part of the definition, I think, to their detriment. Let’s start with
what sustainability is, use it as a foundation, and then move on to the factors that make it more or
less desirable rather than muddying the waters from the start.