This document discusses environmental sustainability and the importance of photosynthesis and ecosystems. It makes the following key points:
1) Sustainability means meeting present needs without compromising the future, as defined by the Brundtland Commission in 1987.
2) Photosynthesis is the sole means of introducing energy into ecosystems and is crucial for all life through plants, trees and grasses.
3) Soil is a complex living system created by ecosystems, and although slowly formed, it is a fragile non-renewable resource if ecosystems are damaged.
4) Quotes from ancient writers show that environmental degradation is not a new problem, with references from 200AD and 340BC describing deforestation and soil
2. Sustainability
sustain: provide with the basic necessities required to
support or preserve life livelihood, or existence;
maintain or keep (an action or process) going
continuously
sustainable: “Ecology” (esp. of development) that
conserves an ecological balance by avoiding depletion
of natural resources; that may be maintained, esp. at a
particular level
-
Oxford Canadian Dictionary
3. Our Common Future
Our Common Future, published in 1987 by the
World Commission on Environment and
Development (the Brundtland Commission),
defined it as development that “seeks to meet the
needs and aspirations of the present without
compromising the ability to meet those of the
future.”
- Oxford Concise Dictionary of Ecology
4. Photosynthesis = Energy
There are many different types of ecosystem but the
foundation of all of them, and therefore the basis
for all life on earth, is photosynthesis.
It is the only way that energy is introduced into
the system…Within an individual ecosystem
photosynthesizers (such as plants, trees and
grasses) provide the basic energy input.
Responsible grazing seeks to maximize solar
collection through optimal plant management.
5. The first law of thermodynamics
Energy is conserved, that is to say, indestructible. There
is always the same total amount of energy in the
universe. It can be neither created, nor destroyed; it just
changes form, such as from chemical energy in fuel, to
heat. Energy is simply available or unavailable for use.
6. The second law of thermodynamics
The entropy of the universe tends to a maximum.
Entropy is the measure of the degree of disorder in a
system. As entropy increases systems evolve from a
state of relative order to one of disorder. Entropy can
also be thought of as a measure of the amount of
unavailable energy in a system.
7. Recycling
The fact that the earth is a closed system means
that nothing can get out. All waste products must
go somewhere.
The recycling of the materials necessary for life
is an essential function of all ecosystems and
the other physical and chemical processes on
earth.
8. Soil
Soil is the product of an ecosystem – it has been
created by living plants and animals and it continues
to rely on them to remain fertile and productive.
Fertility is built up and maintained as an active
process through the interaction of the plant cover,
the existing soil, the work of decomposers and other
environmental factors such as rainfall and
temperature. All of these processes make the
various types of soil found in different parts of the
globe one of the most complex living systems on
earth.
9. A Fragile Resource
Although soils are created over time this process is, on a
human timescale, so slow that the soil is in effect a nonrenewable resource. It is also a highly fragile one.
Ecosystems develop naturally in a way that protects the soil
on which they depend. Once the trees and plants of an
ecosystem are destroyed or badly damaged then the
underlying soil is very quickly subjected to severe strain and
can be easily destroyed or eroded away by wind and rain
leaving only a degraded remnant.
10. When was this written?
“One thing is sure. The earth is now more cultivated
and developed than ever before. There is more
farming with pure force, swamps are drying up, and
cities are springing up on unprecedented scale.
We’ve become a burden to our planet. Resources
are becoming scarce, and soon nature will no longer
be able to satisfy our needs.”
- Tertullian, Roman theologian, 200 A.D.
11. Here’s Another One…
“What now remains compared with what then existed is like the
skeleton of a sick man, all the fat and soft earth having wasted
away, and only the bare framework of the land being left… there
are some mountains which now have nothing but food for bees,
but they had trees not very long ago… there were many lofty
trees of cultivated species and… boundless pasturage for flocks.
Moreover, it was enriched by the yearly rains from Zeus, which
were not lost to it, as now, by flowing from the bare land into the
sea; but the soil it had was deep, and therein it received the
water, storing it up in the retentive loamy soil, and… provided all
the various districts with abundant supplies of springwaters and
streams, whereof the shrines still remain even now, at the spots
where the fountains formerly existed.”
- Plato, Critias, ca. 340 BC
20. Our Task…
“The most important task in all human history has been
to find a way of extracting from the different ecosystems
in which people have lived enough resources for
maintaining life – food, clothing, shelter, energy and
other material goods. Inevitably this has meant
intervening in natural ecosystems. The problem for
human societies has been to balance their various
demands against the ability of the ecosystems to
withstand the resulting pressures.”
- Clive Ponting, from A Green History of the
World: The Environment and the Collapse of Great
Civilizations