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 Toward
a stewardship of the Global Commons:
engaging “my neighbor” in the issue of sustainability
By
members of the Critical Issues Committee, Geological Society of America
Part I
WHAT DO WE MEAN BY THE GLOBAL COMMONS?
A. R. Palmer,
Institute for Cambrian Studies, Boulder, CO.
In
old English law, the common (or commons) was a tract of ground shared
by residents of a village, but belonging to no-one.It might be grazing grounds, or the village square, but it was
property held in common for the good of all.
Sustaining human
civilization on Earth at acceptable levels requires recognition of the
place of human beings in the “web of life” and the role human beings
play in modifying the world on which we live and the natural systems
which maintain the Biosphere of which human beings are just a part.
We must take individual personal responsibility for the Atmosphere,
Hydrosphere, Lithosphere and Biosphere – the Global Commons – that we
all share.
Throughout human
history, we let the noxious gases and particles from our cooking, heating,
industrial activities, and, more recently, our various modes of transportation
and delivery of goods drift away on the wind, without really considering
what happened to these materials downwind from us.
How much responsibility do we bear for acid rain, persistent
smog, increasing atmospheric carbon dioxide, and disturbances of the
stratospheric ozone layer?
We have mined
water from underground as if the supply was inexhaustible. We have discharged our industrial effluents and our sewage, into
streams or lakes, or into the ground, with little thought to the consequences.
Some results are dramatic drops in the level of the water table
under many key agricultural areas and cities, ground water and surface
water no longer safe to drink by humans, and diminished or destroyed
fisheries. Even as we deplete
our potable water, the population in those areas of depletion continues
to increase, further straining an exhaustible resource.
We have plowed
the ground and heavily fertilized and/or irrigated our crops, realizing
short-term gain, but not readily recognizing the long-term losses.
Some results are soil erosion with accompanying loss of soil
depth, nitrification of lakes and streams adjacent to farmland, and
loss of formerly productive agricultural land by salinization of soils.
We have cut forests for fuel and timber,
and to create pastures or cropland. We have further altered the landscape by expanding
cities and industries, or by building dams to augment our water needs,
supply power for our homes and factories, or control floods that might
wash away our structures. We
have overfished our rivers, lakes and oceans, and overhunted many of
our game animals. We have introduced
foreign animals or plants into new areas where they have no natural
controls on their spread. We
have, as human beings, disrupted
ecological systems that have existed in balance with their surroundings
for millennia.
We must constantly
remind ourselves that we are an interdependent component of those ecosystems
that form the complex web of life on this planet.
We each have a responsibility to be aware of our dependence on
the successful function of all components of the Global Commons for
the future well-being of humanity.
Suggestions
for illustrating the concept of the Global Commons.
DEMONSTRATION
1: One way to drive home the concept of the limited
atmosphere capable of supporting life on Earth is to take the common
classroom globe (often about 40 cm in diameter) and ask students to
calculate the distance represented by one millimeter (about 30 km). Most people live below an elevation of 5 km
(about 15,000 feet). Have the
students discover that the portion of the atmosphere upon which the
existence of human, plant and other animal life depends– the Biosphere
– is about the thickness of a sheet of paper.
DEMONSTRATION
2: One way to make the point about over-pumping
an aquifer would be to develop a siphon at one end of a small aquarium
filled with water-saturated sand where you can control water input at
the other end to be less than the rate the water is siphoned off. The level of saturated sand will drop as withdrawal exceeds supply.
With the same setup, pollution can be simulated by a fluorescent
dye that could be introduced into the supply end and later detected
in water coming out of the siphon.
DEMONSTRATION
3: How much of our food comes from irrigated farmland
susceptible to salinization? Salinization
can be effectively demonstrated by evaporating the tap water normally
used for watering plants, or local well water if available, in a shallow
dish and noting the accumulated residue. Successive additions of more water to be evaporated in the same
container will demonstrate a buildup of deposits. How deep is the productive soil in your area? If surface soil loss is only 1 mm per year,
how long will that productive soil last?
How is the soil replenished?
At what rate?
DEMONSTRATION
4: Obtain an aerial photograph
of your area, or check the landscape on your next airplane flight, note
how much of the landscape has been affected by human activities, and
what was the nature of those activities.
Consider what the area might have looked like before human development
and then consider the cumulative effect of this ongoing development
on natural ecosystems and regional environmental processes.
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