6EFK
United States
Environmental Protection
Agency
Office of Policy,
Planning, and
Evaluation
EPA230-F-92-008
May 1992
Climate Change
Discussion Series
Biodiversity
Biodiversity, also called "biological diversity" or
"ecological diversity," refers to the variety of life
on earth. Biodiversity is often assessed at three levels—
ecosystem, species, and genetic. An ecosystem in-
cludes all the plants and animals in an area, to-
gether with their physical-chemical environment.
Examples include a forested watershed, a fresh-
water pond, a salt marsh, or a coral reef. The spe-
cies level refers to populations of individual spe-
cies, such as white-tailed deer or large-mouth bass.
The genetic level is the gene pool found within
each population. That gene pool is the result of
gradual adaptation to climatic and other changes
over time.
Existing patterns of biodiversity reflect gradual
adaptations to changes over thousands of years.
Future rates of climatic change may include glo-
bal warming of 1.5° to 4.5°C (3° to 8°F) within a
century. This would be far too rapid for plant ad-
BASS POPULATION
GENETIC
DIVERSITY
Value of Biodiversity
Biodiversity is a national and global resource. In many
parts of the world, biodiversity is being reduced by
population pressure and consequent overharvesting,
deforestation, or desertification. Rapid climate change
will accelerate these losses, with significant economic
consequences. One of the main benefits of slowing the
rate of climate change is protection and preservation
of biodiversity.
Ecosystem Values
A healthy ecosystem, with its full complement of plants
and animals, provides many services to society. A forest
ecosystem can prevent soil erosion, reduce flooding,
detoxify chemicals in air and water, improve the local
climate, and sequester carbon that would otherwise
contribute to global climate change. A coral reef may
protect beaches, serve as a tourist attraction, and pro-
vide habitats for interesting and valuable species of
fish, dams, and lobster.
Species Values
Society may place special value on large or colorful
species, especially if they have been so reduced in
numbers that they are listed as threatened or endan-
gered on the local, national, or global scales. These
species are often of exceptional scientific and educa-
tional interest, and may serve as the basis for
"ecotourism," bringing a significant influx of foreign
exchange to a country.
Genetic Values
The genetic material in wild plants and animals rep-
resents the raw material required for traditional se-
lective breeding of improved domestic varieties of crops
and livestock. It also provides the genetic codes for
bioengineering and the field or laboratory production
of many chemicals with great potential value in medi-
tineand industry. Finally, geneticdiversity now present
in small populations may be of great future value be-
cause those populations have already adapted to cli-
matic conditions that will be widely prevalent in years
to come.
NOTE: Climate change refers to potential modification of the earth's climate resulting from increasing atmospheric concentrations of greenhouse gases such as carbon
dioxide (CO2), methane (CH<), nitrous oxide (N2O), and chlorofluorocarbons (CFCs). Through a naturally occurring process known as the "greenhouse effect," these
gases act to warm the earth by trapping heat in the atmosphere. This process plays an important role in maintaining the earth's current temperature and climate. By
increasing concentrations of greenhouse gases, human activities are trapping more heat in the atmosphere and potentially changing the earth's climate.
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aptation, leading to die off of for-
ests and loss of animals depen-
dent on forests. Similarly, species
populations in coastal ecosystems
may decline from the combined
effects of pollution, warming, and
sea level rise. Natural and man-
made barriers may increase
biodiversity loss by blocking mi-
gration (e.g. by blocking the north-
ward movement of forest species
and the inland movement of those
in coastal wetlands.)
Those populations increasing in
ecosystems stressed by climate
change often will be pestilent, such
as bark beetles attacking weakened
trees or toxic algae displacing other
coastal plant life. In regions where
droughts become more extensive
or prolonged, habitats required by
ducks, frogs, and many other species
dependent on ponds and streams
will continue to decline. Forests
will become more susceptible to
forest fires, eliminating certain spe-
cies but creating conditions suit-
able for others adapted to the post-
fire environment.
Options to Preserve Biodiversity
Individuals, public and private or-
ganizations, industry, and all lev-
els of government, can help pro-
tect biodiversity by supporting poli-
cies such as those discussed below.
Manage Forests Sustainably
Tropical and temperate forests are
important treasure houses of
biodiversity. They should be man-
aged to maintain those values as
well as the other goods and ser-
vices they provide.
Reduce Pollution Stress on
Ecosystems
Ecosystems stressed by air or wa-
ter pollution are more likely to suffer
additional degradation from the
stress of rapid climate change. There-
fore, reducing acid deposition,
ground-level ozone, toxic metals,
and other pollutants that damage
terrestrial and freshwater ecosys-
tems, and reducing run-off of sedi-
ments, nutrients, and biocides into
freshwater and coastal ecosystems
can help preserve biodiversity.
Expand and Link Parks and
Preserves
Many species of birds and mam-
mals need large natural areas to
ensure their survival. When full
protection ("wilderness" status) is
not possible, it may be possible to
create buffer zones in which re-
source extraction does not have ad-
verse effects on the wide-ranging
species. In addition, corridors of
natural vegetation Unking preserves
can partially compensate for the
problems of habitat fragmentation
by helping ensure dispersal, recolo-
nization, and gene flow.
Restore Degraded Habitats
Reforestation programs planting
a wide variety of native trees can
greatly enhance the biodiversity
of abandoned croplands. Similarly,
restoring freshwater and coastal
wetlands can provide habitats for
waterfowl and many other species.
Maintain Species in Aquaria,
Zoos, Gardens, and Seed Banks
This policy is especially appro-
priate when natural habitats have
been destroyed. It permits pres-
ervation of genetic diversity and
provides a source for reintroduction
of species when habitats have re-
covered or have been restored.
Support Conservation
Organizations
There are many different organi-
zations working to identify pre-
serve, and use biodiversity. Indi-
viduals can help by supporting such
organizations and participating in
their activities.
Based on EPA's Report to Congress, The Potential Effects of Global Climate Change on the United States, 1989; Intergovernmental Panel on Climate
Change, Policymakers' Summaries, 1990; National Academy of Sciences publications, Biodiversity, 1988; and Policy Implications of Greenhouse
Warming, 1991; Izaak Walton League' s,Unpreceden ted Risks:The Effects of Global Climate Change on U.S. Wildlife Resources,1991; World Resources
Institute's, Drowning the National Heritage: Climate Change and U.S. Coastal Biodiversity, 1991.
EPA's Climate Change Outreach Program is designed to raise awareness about climate change and provide assistance to state and local
governments, industry, and non-governmental organizations in the evaluation of cost-effective response strategies. For further information
about this program, please contact Joel Smith at 202/260-8825.
U.S. EPA Climate Change Discussion Series 1992
Global Climate Change Sea Level Rise
Adaptation to Transportation
Climate Change Energy
Forestry Water Resources
Agriculture Biodiversity
Order from: CLIMATE CHANGE INFORMATION
US. EPA
Office of Policy Analysis
Climate Change Division (PM221)
401 M Street, SW.
Washington, DC 20460
USA
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