a stewardship of the Global Commons:
engaging “my neighbor” in the issue of sustainability
members of the Critical Issues Committee, Geological Society of America
SUSTAINABILITY & RESOURCES
E-an Zen, University
of Maryland, College Park, MD
we ponder the future of the human enterprise, questions about material
resources come up. Will they run out? Will they replenish themselves?
Will the demand for them diminish, or will alternatives be found? Without a good estimate of those resources,
we will never be able to predict or improve human welfare. "Malthusians" have a doomsday outlook;
"Cornucopians", a more optimistic view (McCabe, 1998). Yet whichever school of thought seems more
persuasive, the fact remains that we live in a materially closed system. The Earth's resources are finite, so we must
choose how best to use them.
A society needs
reliable information on the resources available to it and on the consequences
of their use. How it will act
on that information will depend on its value system.
For example, a society may place a high priority on fair distribution
of wealth. We in the developed
nations have an opportunity to demonstrate a commitment to use resources
in a sustainable way. Do we
want to act responsibly toward future generations of our species and
toward other life forms as well?
are whatever the society at a given moment either uses or recognizes
as potentially usable. Because that list changes with society's needs
and technology, what is useless one day may become vital the next. As recently as a century ago, aluminum, petroleum,
and uranium were not significant resources.
to think of "resources" as the stuff we take from the ground:
metal ores, coal, petroleum, groundwater, limestone, phosphate, quartz
sand and rock. The earth's resources, however, also include
living things that are subject to human exploitation.
Trying to inventory
resources for the future, thus, is like aiming at a moving target. Yet some statements will remain valid for three reasons: (1) except
for energy input from the sun, which supports and maintains our “ecosystem
services”, the earth is a closed system having a fixed quantity of materials.
(2) Both the extraction and processing of materials and preservation
of the environment require energy, itself a resource.
(3) Using a material generally changes its state of aggregation,
and its adaptability for future use.
Thus, the processing of materials, including recycling or re-aggregating
waste material into usable form, causes a thermodynamically inexorable
loss of useful energy and/or material. With regard to Earth’s material resources,
there is no free lunch!
To these factors
must be added both an increasing global population (projected to reach
about 9 billion people by 2050), and a higher per capita consumption
rate reflecting "improved" standards of living.
Obviously, resource considerations are crucial for the success
of the human enterprise.
resources are grouped as "nonrenewable" and "renewable". Nonrenewable resources (examples: ores, petroleum,
coal) replenish at geological rates that are much too slow to benefit
human society. Once consumed,
such finite resources are effectively removed from our inventory. New discoveries or more efficient extraction
methods merely postpone their inevitable exhaustion.
resources (examples: timber, fishstock, groundwater) have rates of natural
replenishment commensurate with the time- scales of human society (see
DEMONSTRATION 1 below). However,
to consume such resources faster than they can replenish themselves
is like withdrawing funds from a bank account faster than we make deposits;
sooner or later that account will run out.
We have often been guilty of just such overwithdrawal.
Examples include overfishing, poor husbandry of arable and pasturable
land, overpumping of aquifers, destruction of entire ecosystems such
as Russia's Aral Sea. Such "local" losses can have large
systemic effects (see DEMONSTRATION 2 below).
use of substitutes, recycling, and conservation can slow down depletion
of a renewable resource (i.e., the amount of consumption that exceeds
its renewal by all processes, natural or engineered), but they cannot
halt the process. To make a "renewable" resource truly
renewable, the rate of consumption must not exceed the gross rate of
renewal. Reaching a "sustainable
world" will demand many changes to our priorities regarding resource
Some vital resources,
such as the "environment", are not material objects. A healthy environment is a composite of many other items (e.g.,
water chemistry and temperature, nutrients and other chemicals in the
soil, good habitats for wildlife).
A natural place of beauty and wonder is an intangible but valuable
resource. A less obvious intangible resource is the future
generation's options, i.e., their capability to make real choices. Options are not fixed commodities, but surely
they will be important for future societies. Like the options available to us today, many future options require
the availability of material and energy. Even if an earth material is not dispersed through use, their very
processing automatically reduces future options of their use.
The results of
human exploitation of resources cannot be predicted by looking at one
commodity or one social force at a time.
Calculation of the effects of use and depletion of materials
on the public commons (see Part I) must also
include human values and cultural habits.
Justus von Liebig, a 19th century agricultural chemist, recognized
the complexities that arise in a situation where humans and natural
forces work interactively. Historian Elliott West put von Liebig's view
this way: "an organism's limits are set, not by the maximum profusion
of necessary things, but by those things' minimum availability.. Look
.. for how much is available when vital supplies are the tightest, lowest,
What is true
for an organism is true for ecosystems.
Can we identify the "vital supplies", their mutual
relations and their future trends?
Can we recognize the factors of "minimum availability"
while there is yet time? Or will they surprise us and perhaps blindside
us? Surely we need to be thinking
about these issues.
To maintain a
society's standard of living requires consumption of resources at some
level. In Part XX of this series, we will explore
this subject within the "sustainability" context.
The author thanks
Christine Turner of the US Geological Survey, Denver, for her contribution
to the ideas and her critique of the text.
(1) Ask your
students to list the resources that they encounter in one day of their
activities, using the following categories:
"Nonrenewable" resources are those that may be replenished
rates much exceeding the human time scale:
for example, fossil fuel
(what should be included here?), metals
(where do they come from?).
"Renewable" resources are those that may be replenished on
time scale, but only if the rate of withdrawal
or destruction does not
exceed the rate of replenishment: for example,
timber, fishstock, soil,
groundwater, environmental quality, mixed
forests, ozone layer.
(2) Pick any
material object: the gasoline you pump, a metal paper clip, the bricks
of the building, the gravel in a driveway, a toothpaste tube, or a molded
plastic chair. For that object, ask the students to identify
the resources embodied in it: where did the material come from, and
in what original form? Ask them
to discuss what processes were needed to produce the object (e.g., mining,
harvesting, refining, waste disposal, ecosystem disturbance, transportation,
energy use). What renewable
or nonrenewable resources were used in the processing?
Are there substitutes that would require less energy and material? How essential is this particular product to
the students' comfort or well-being?
Could they make do with less?
What would be the tradeoff in making a more frugal choice? Who might benefit from that choice, and in
In a recent book,
"Waiting for Aphrodite", Sue Hubbell, author-naturalist-apiarist,
described recent stresses to communities of the green sea urchin, Strongylocentrotus droebachiensis, which lives off the rocky coast
of Maine. The population density
of this sea urchin seems to go through cycles; in the 1980's they thrived. Sea urchin eggs were a delicacy for the affluent
Japanese. When their local stock
was becoming depleted at about this time, the Japanese merchants turned
to Maine for a substitute. Meanwhile,
needing an alternative source of income because the coastal cod and
haddock fishery had collapsed through overfishing, the fishermen of
Maine started to dive for the green sea urchins.
Soon, however, the catch began to fall alarmingly.
Green sea urchin eggs are fertilized by sperm which last only
a few minutes in seawater, so large congregations of urchins are essential
for the species to survive. Large
congregations attract fishermen as well, but, luckily for the urchins,
the Japanese yen weakened, the demand for pricey urchin eggs fell, and
a Russian source became available. Sea urchin "farming" is now being
explored as a steady source of supply, so the natural communities of
Maine sea urchins might yet recover.
How might the
disappearance of green sea urchins affect the ecology of the coastal
waters? We do not know. Some years ago scientists thought that the long-spined black sea
urchin, Diadema antillarum,
of the Caribbean region was a useless species.
Then it was discovered that coral and sponge larvae can attach
themselves to reefs only on surfaces kept clean by the sea urchins,
which graze on the algae. So
the "useless" sea urchins turn out to be essential to the
coral reef ecosystem, after all.
story may be minor in the scale of things, but it provides a good example
of the intricacies of an ecosystem.
If we act without adequate knowledge, we can easily throw an
ecosystem out of balance, possibly irreversibly.
Hubbell, Sue, 1999, Waiting for Aphrodite:
journey into the time before bones.
and Mifflin. 242 p.
McCabe, P.J., 1998, Energy resources -
cornucopia or empty barrel? American
Petroleum Geologists Bulletin, v. 82, p. 2110-2134.
von Liebig, Justus, 1847, Chemistry in
its applications to agriculture and physiology:
and Walton. 418 p.
West, Elliott, 1998, The contested plains:
Indians, goldseekers, and the rush to Colorado.
of Kansas. 422 p.