Download Why should we care about biodiversity?

BIODIVERSITY
Refers to the broadly diverse forms in which
organisms have evolved and is considered at three
levels:
1. Genetic diversity: variation in genes enabling
organisms to evolve and adapt to new conditions;
2. Species diversity: the number kind and
distribution of species within an ecosystem;
3. Ecosystem diversity: the variety of habitats and
communities of different species that interact in a
complex web of interdependent relationships.
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THREATS TO BIODIVERSITY
"Virtually all students of the extinction process agree
that biological diversity is in the midst of its sixth great
crisis, this time precipitated entirely by Man."
-- E.O. Wilson
Harvard University
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Currently, more than 10,000 species become
extinct each year
Rate has increased alarmingly in recent years.
The central cause of species extinction is destruction
of natural habitats by human beings.
o Habitat destruction (burning or felling of oldgrowth forests)
o Overexploitation (over hunting of elephants and
rhinos)
o Pollution (industrial emissions that cause acid rain)
o Global climate change (the greenhouse effect and
destruction of the ozone layer)
o Invasion by introduced species (displacement of
native songbirds in the U.S. by European starlings)
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Threats driven by underlying social conditions
o Increased per-capita consumption
o Poverty
o Rapid population growth
o Unsound economic and social policies.
VALUE OF BIODIVERSITY
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Human survival may depend upon reversing this
accelerating threat to species diversity.
Among the millions of undescribed species are
important new sources of food, medicine
When a species vanishes, we lose access to the
survival strategies encoded in its genes through
millions of years of evolution.
We lose the opportunity to understand those
strategies, which may hold absolutely essential
options for our own future survival as a species.
We lose emotionally; we lose the unique beauty,
and the unique spirit, associated with that life
form.
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Many indigenous human cultures have also been
driven to extinction by the same forces, which
have destroyed and continue to threaten nonhuman species.
Since 1900 more than 90 tribes of aboriginal
peoples have gone extinct in the Amazon Basin.
Nearly every habitat on earth is at risk:
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Rainforests and coral reefs of the tropics,
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Salt marshes and estuaries of our coastal regions,
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Tundra of the circumpolar north,
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Deserts of Asia and Australia,
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Temperate forests of North America and Europe,
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Savannahs of Africa and South America.
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TROPICAL RAINFORESTS
Among the most diverse of all terrestrial ecosystems
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Covering only 7% of the planet's surface, these
forests comprise 50-80% of the world's species.
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40 million to 50 million acres of tropical forest vanish
each year
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About 1.5 acres per second
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Trees for lumber
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Land cleared for agriculture or other
development.
SOLUTIONS
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A quarter of the Earth's total biological diversity is
threatened with extinction within 20 to 30 years.
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Solution lies in increased educational efforts.
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Develop sustainable resources.
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Rich and poor nations must strive for cooperative
stewardship of global biodiversity.
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WHY SHOULD WE CARE ABOUT BIODIVERSITY?
Biodiversity is a necessity, not a luxury.
A one-acre patch of elm trees produces oxygen,
removes carbon from the atmosphere, and
captures
at least 16 tons of airborne dirt, which rain then
washes back to the ground as productive soil.
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Provides direct benefits like food, medicine, and
energy;
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Affords us a "life support system."
Required for the recycling of essential elements,
such as carbon, oxygen, and nitrogen.
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Responsible for mitigating pollution,
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Protecting watersheds,
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Combating soil erosion.
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Buffer against excessive variations in weather
and climate
Protects us from catastrophic events beyond
human control.
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Biodiversity is important to the global
economy.
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Modern agriculture, depends on new genetic stock
from natural ecological systems, $3 trillion global
business;
Nature tourism generates some $12 billion
worldwide in annual revenues.
United States: economic benefits from wild plants
and animals make 4.5% of the Gross Domestic
Product.
1988:
 Worldwide commercial trade in wild plants
(excluding timber) and animals valued at $5 billion.
 20 best-selling US drugs revenues of $6 billion
worldwide,
 All relied on plants, microbes, and animals for
development.
 Each wild plant that provides chemical basis for
new drugs generates at least $290 million annually
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Biodiversity is essential for ensuring
food security.
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Major food crops, corn, wheat, and soybeans, depend
on genetic material to remain productive and healthy.
Breeders and farmers rely on genetic diversity of
crops and livestock to increase yields and respond to
environmental changes.
Plant breeding, wild genetic stock and other sources,
account for half the gains in agricultural yields in
United States from 1930 to 1980.
Earth's oceans, lakes, and rivers contain food
resources. Food production from wild stocks of fish single largest source of animal protein for expanding
population.
In 1994, more than 10 billion pounds of fish, valued at
about $4 billion, caught and sold in the United States
alone.
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Teosinte,
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A wild relative of corn discovered in Mexico during the
1960s, resists four of the eight major diseases that
kill corn in the United States.
Had it been available to U.S. farmers in the 1970s,
losses of $1 billion could have been avoided when
disease wiped out uniformly susceptible varieties.
Thanks to Teosinte, prices for grain-fed meats, soft
drinks, and other corn-related foods have been kept
low.
Genetic biodiversity protects American farmers and
consumers alike.
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Biodiversity safeguards human health.
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79% of top-selling 150 prescription drugs in US
originate in nature.
Many synthetic drugs, including aspirin, first
discovered in wild plants and animals.
Roughly 119 pure chemical substances extracted
from 90 species of higher plants used in
pharmaceuticals.
Traditional medicine:
 Relies on species of wild and cultivated plants,
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Basis of primary health care for 80% of people in
developing countries.
U.S. imports more than $20 million of rain forest
plants per year for medicinal properties.
Only 2% of the 250,000 described species of
vascular plants screened for chemical compounds.
Taxol, new drug from the Pacific yew tree,
o Used to treat ovarian cancer.
o In 1960, a child with leukemia had a 1 in 5
chance of remission.
Anti-cancer drugs developed from wild
periwinkle - chance of survival 80%
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Biodiversity provides recreational
opportunities.
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Provides recreational opportunities & aesthetic
value.
In 1991, recreation associated with wild birds
generated nearly $20 million and 250,000 jobs in
the United States,
 Exceeded many Fortune 500
companies.
Saltwater recreational fishing in the U.S.
generates more than $15 billion annually
 Provides over 200,000 full-time jobs
U.S. parks brought in $3.2 billion from visitors in
1986.
Tourism in Kenya amounted to $400 million.
 The economic value of viewing
elephants alone totaled $25 million in
1989.
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Large economic revenues reflect the high value
people place on recreation involving biodiversity.
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Biodiversity and the issues that affect it
cross all national borders.
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Air and water pollution do not respect national borders
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Acid rain, air pollutants mix with falling rain,
 In North America, industrial emissions
cause acid rain
 Sugar maples in Canada, threatens
future maple syrup production.
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Global climate change most serious threat to life
 Carbon released from human-induced
activities
 Burning of fossil fuels, forests, and other
natural habitats
 Tropical forest burning accounted for
25% of all carbon released into the
atmosphere over the past decade.
 Build-up of carbon dioxide, greenhouse
gases, ozone depletion causing climate
change.
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Catastrophic consequences for wildlife and
ecosystems
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Warmer temperatures cause shifting of
agricultural lands hundreds of miles north
 Cause severe coastal flooding.
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Species migrate to keep up with optimum
conditions,
 Rate of change would be too fast for
many to adapt.
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Loss of biodiversity can even threaten national
security.
 Many national and international conflicts
over water, land, and other natural
resources.
 Environmental conflicts lead to mass
migrations of people
 Strain national budgets, public
infrastructure, and international relations
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Rates of species extinction are
unprecedented.
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Virtually all of the loss is caused by human
activities,
Mostly through habitat destruction and over
hunting.
Over 34,000 plant species and 5,200 animal
species around the globe are threatened with
extinction
North America:
 98% of virgin forests have been
destroyed,
 54% of wetlands have been lost
 Over the past 500 years
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200 species of plants
71 species & sub-species vertebrates
Extinct in North America alone
Another 750 species endangered or
threatened.
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Only 13% of the approximately 14 million species
on Earth described by scientists.
Human pressure on biological resources, increase
rates of extinction
The undersea kelp forest ecosystems
 Northern Pacific rim the richest marine habitats
known
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Home or breeding ground of many species of fish
and sea otters.
Sea otter: western coast of Canada and US
Hunted almost to extinction 19th and 20th Century
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Invertebrates - the sea urchin - left without major
predator.
Sea urchins increased dramatically; consumed
the kelp and other seaweeds
Became a barren undersea terrain.
Conservation efforts throughout the latter half of
the 20th century protected and reintroduction of
sea otter to ecosystems; Kelp forests once again
thrive.
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What is being done to conserve biodiversity?
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1993 public opinion poll, 89% of the public
agrees that human beings have an ethical
responsibility for protecting plant and animal
species.
78% believe greater protection for fish and
wildlife habitats on federal forest lands
Public concern benefits society indirectly
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1972: public outcry over the declining populations
of the American bald eagle
The U.S. banned the production and sale of the
pesticide DDT
This chemical was later identified as a serious
cancer-causing agent in humans.
Global:
 International Convention on Biodiversity.
 Recognizes conservation of biodiversity as global
issue
 More than 100 countries have ratified it.
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What can we do?
Individuals:
Conserve biodiversity by
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Investing in and supporting environmentally sound
businesses;
o Supporting local, national, and international
conservation efforts;
o Minimizing our consumption of gasoline, electricity,
and material goods;
o Becoming informed about legislation that affects the
world's biodiversity and sharing our concerns with
our elected representatives.
Society
o Curb our use of energy,
o Eliminate our consumption and use of
threatened species,
o Support the transformation of national and
international policies to those that are more
sustainable and less harmful to biodiversity.
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