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Many biologists who
study biodiversity confine themselves to the objective assessment
of ecological processes. Others believe that scientists should
comment on the moral, philosophical and political aspects of biodiversity.
The first approach
risks losing many species of plants and animals to exploitation
or development, whereas the second leads people to question the
impartiality of scientific conclusions. Which
do you think is preferable?
Arguments
for protecting biodiversity fall into two categories:
Biodiversity has an intrinsic
value that is worth protecting regardless of its value to humans.
This argument focuses on the conservation of all species, even if they
are ecologically equivalent species.
Biodiversity performs a number
of ecological services for humankind
that have economic, aesthetic or recreational value. This argument focuses
on conserving ecologically nonequivalent species since ecologically
equivalent ones are redundant in terms of services rendered
(G.
Bell, pers comm).
Both points of view
(intrinsic and anthropocentric) need not be contradictory, as
they serve the same ultimate purpose. Yet they often are considered
incompatible because they stem from two very different philosophies:
one which views nature as innately valuable and one that regards
it as economically valuable.
Both
the intrinsic value and the anthropocentric values are presented
in this page. The debate regarding the value of biodiversity and
the need to protect it is still very hotly contested. The reader
is left to draw their own conclusions from the arguments presented.
Intrinsic
Value
The first argument
for the intrinsic value of biodiversity is the idea that humans
are part of nature.
"We know now what was unknown to all the preceding
caravan of generations: that men are only fellow-voyagers with
other creatures in the odyssey of evolution... Above all we should,
in the century since Darwin, have come to know that man, while
now captain of the adventuring ship, is
hardly the sole object of its quest, and that prior assumptions
to this effect arose from the simple necessity of whistling in
the dark." - Aldo
Leopold, A Sand County Almanac.
The argument for conservation
of biodiversity often emphasizes the need to facilitate continued
evolution. As humans are and were part of nature, they benefited
from the evolutionary process. The tenet that humans are part
of nature questions whether humans should endanger their own milieu
and the process from which they stem.
A corollary to the
above argument
is reflected in the Noah principle , named for the biblical
Noah who saved one pair of every creature on earth in the Ark,
which argues that the usefulness of a species is not considered
when discussing its conservation, but rather its very presence
in the long history of evolution is sufficient to warrant its
preservation.
"The
non-humanistic value of communities and species is the simplest
of all to state: they should be conserved because they exist
and because this existence is itself but the present expression
of a continuing historical process of immense antiquity and
majesty. Long standing existence in Nature is deemed to carry
with it the unimpeachable right to continued existence"
D.Ehrenfeld, Conserving Life on Earth 1972
Environmental
ethicists also stress that humans should protect biodiversity
because they are the cause of most of the loss of biodiversity
through loss of habitat, overexploitation and other perturbations.
"99 percent of
all species that ever lived are now extinct. But I think we have
an obligation, now, in our generation and in foreseeable generations,
to try to protect every species, try to maintain every species,
because virtually every species that is going extinct now is going
extinct due to human activity not because of natural processes"
R. Noss, 1996
(Takacs,
1996)
Ethics
and environment: extension of rights to species and landforms
While many
people will challenge us with the notion that protection of the
environment is morally good, philosophy and religion have not incorporated
the concept of nature conservation; it is not yet included in our
ethical framework. The process of inclusion of these issues is one
of social evolution. The concept of stewardship, however, is one
firmly ensconced in the Judeo-Christian doctrine.
Some
people suggest that the idea of biodiversity reaches towards oneness,
toward a unity of all living and non-living things. When anthropocentric
attempts at valuing biodiversity are put aside, what remains are
the realm of the emotional, spiritual and religious justifications.
However, skeptics counter that the spiritual and religious holds
of biodiversity on humans may simply be due to our lack of understanding
of it. (Takacs,
1996 , p.
98)
The noted Harvard biologist
E.O. Wilson champions the idea that love of nature has been "hardwired"
into us by natural selection. The religious feelings that the
concepts of biodiversity and nature can arouse in some can be
seen as a natural extension of a tendency to focus on life and
lifelike processes. Wilson coined this idea "Biophilia"
It is pointed out that
humans, while removed from nature, still need to be surrounded
by nature and they respond to this fundamental need by visiting
natural parks and bringing nature into their daily lives with
pets and plants. But can this apparent love for nature be interpreted
as love for biodiversity? Indeed, the notion of biophilia is often
countered by the perception that humans want the nature surrounding
them to be managed and artificial - green lawns and no pests -
not natural and diverse.
(A great
reference for more information is a book entitled The Idea
of Biodiversity by Takacs,
1996)
Anthropocentric
Value
While intrinsic arguments
for protection of biodiversity are compelling, it is ultimately
arguments of human benefit that pragmetic conservationists find
most appealing: as humans, we are inextricably and wholly dependent
on this diversity of living things for survival.
Biodiversity, encompassing
genetic diversity, species, populations, communities and ecosystems,
and landscapes and regions, provides countless benefits to humans
at all these scales. Some of these benefits include:
Economic benefits,
both direct and indirect;
Aesthetic benefits;
Scientific and ethical
knowledge;
Insurance against
the future
Economic
benefits
The notion
that biodiversity has provided us with many benefits is well understood.
Some of these benefits come in the form of goods that can
be directly valued and costed because they provide something that
can be extracted and sold. These goods include everything from all
the domesticated agricultural crops that form the basis of the world's
food supply, to medicines that protect and cure us to the fibres
that make up the clothes we wear. Thus biodiversity is widely valued
as food pantry, genetic storehouse for biotechnology and a place
to retreat to when we need to get away from our hectic urban existence.
Biodiversity also provides
critical indirect benefits to humans that are difficult to quantify
because we have never had to put a price tag on them. These benefits
encompass ecosystem services , such as air and water purification,
climate regulation, and the generation of moisture and oxygen.
A group of ecologists who recently attempted to quantify the price
of replacing these ecosystem services calculated that they would
cost over $3 trillion. That's greater than the entire global GNP!
In other words, the world cannot afford to replace these services,
therefore we must work to protect our ecosystems.
Natural communities
maintain proper gaseous concentrations in the atmosphere and prevent
rapid climate changes. Drastic changes in the Earth's atmosphere
can have catastrophic effects. Such changes are believed to have
led to the disappearance of dinosaurs from Earth 65 million years
ago. Much less drastic changes resulted in several global ice
ages, the last of which ended 10 thousand years ago.
Vegetation helps recycle
moisture into the atmosphere. A single corn plant (1 lb dry weight)
can transfer 60 gallons of water from soil to atmosphere in a
few months. A single rainforest tree, in its 100 year lifespan
can transfer approximately 2.5 million gallons from soil to air.
Their role in the hydrologic cycle is crucial.
A multiplicity of
organisms is required to create soils and maintain fertility through
complex cycles and interactions. Plant roots break up rock to
create soil particles, small animals like earthworms, mites, insects
and millipedes help give soil its texture and fertility and are
crucial to its aeration. Even tinier soil microorganisms and fungi
are responsible for cycling essential nutrients like nitrogen,
phosphorus and sulfur and making them available to higher plants.
And their numbers are staggering. A gram of fertile agricultural
soil may contain 2.5 billion bacteria, 400
000 fungi, 50 000 algae and 30 000 protozoa. All these organisms
have particular functions and interact with each other and with
their physical environment to create the fertile soil that humans
depend on for agricultural production.
Natural ecosystems
also help absorb the wastes we create and render them nontoxic.
Wetlands are large filters which purify freshwater and remove
heavy metals and other contaminants from it. We often depend on
rivers to flush away and break down the sewage and effluents that
we put into them, which again depends on the array of small and
large organisms that decompose and transform wastes in water.
Soil organisms can slowly decompose food items, paper products
and other wastes produced by human activities. (Erlich
and Erlich, 1992)
Economic arguments
for protecting biodiversity are criticized for being too utilitarian
and human-centered. Indeed, an excessive emphasis on the economic
values of different species is seen as dangerous for two reasons:
there is bias towards the protection of species and ecosystems
that have attributable economic value and this perspective may
also lead to the conclusion that ecosystems that are not directly
benefitting humans are worth more to humans developed than undeveloped.
Aesthetic
value and recreation
In North America,
protected wild areas where indigenous organisms live undisturbed
give people a sense of satisfaction in knowing that there are bears
and wolves and rare plants and insects that still exist on their
continent. Natural and wild landscapes are aesthetically pleasing
and provide opportunities to get away from human-dominated landscapes.
They also provide opportunities for recreational activities such
as hiking, canoeing, birdwatching and nature photography.(Erlich
and Erlich, 1992)
This argument is criticized
for two reasons: first, aesthetic value is not necessarily equated
to biodiversity; some of the most aesthetically pleasing landscapes
are poor in diversity of habitats and species (e.g. mountains)
while some unspectacular landscapes are incredibly rich in biodiversity
(e.g. swamps and wetlands). Second, this aesthetic argument is
relevant only to a minority of wealthy citizens in developed countries
and holds little relevance to the majority of the world's population
(Takacs,
1996)
Future potential
While there
are hundreds of examples of known economic and aesthetic benefits
of biodiversity, biologists and other scientists frequently outline
that more is unknown than known. Important ecosystem services and
uses for plants and animals are still unknown and await discovery.
Yet these cannot be discovered, and benefit humankind, if they disappear
before discovery. The threat to biodiversity can be compared to
book burning (the obliteration of former and future knowledge).
Many of our valuable
goods, from spices (cinnamon, pepper) to critical medications
(aspirin, tamoxifen, quinine, digitalis) have been discovered
"accidentally" because plants or animals produced chemicals for
defense or attraction. We would not have otherwise considered
the organisms from which these chemicals originated as valuable
and worthy of conservation.
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