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HABITAT
DEGRADATION
The
fate of the human species is inextricably interwoven with the collective
fates of threatened wild spaces, as well as the plants and animals that
live in them, around the globe. Healthy habitats are integral to healthy
human populations worldwide.
For example,
the importance of rainforests to the health of this planet cannot be
overstated. A seemingly endless list of facts scream the importance
of saving the world's remaining rainforests:
- Over half of Earth's
living species live in the tropical rainforests.
- 20% of the world's oxygen
is produced in the Amazon rainforest.
- Two-thirds of Earth's
fresh water is in the Amazon River basin.
- 70% of the plants found
to be active against cancers come from rainforests. Over 120 prescription
drugs and 25% of all pharmaceuticals are derived from rainforest
materials.
- Rainforests once covered
15% of the earth's land surface; they now cover 6%.
- In less than 50 years,
more than half of the world's tropical rainforests have been destroyed
and the rate of destruction is still accelerating. Over 200,000
acres of rainforest are destroyed every day.
- Some areas of tropical
rainforest have escaped glaciation for 65 million years. This has
allowed these forests to develop an array of life unmatched in any
other ecosystem on Earth.
- Presently, less than
3% of an estimated 300,000 rainforest plant species have even been
studied by scientists. One species, the Madagascar Periwinkle (now
extinct in the wild), increases the survival rate of children with
leukemia from 20% to 80%.
- Pollution can have devastating
effects on human health. For example, effluent or air-borne emissions
from factories can hamper
children's development.
Human
Population Impacts on Biodiversity
Humanity's impact
on the earth has increased extinction rates to levels rivaling the five
mass extinctions of past geologic history, transformed nearly half of
Earth’s land from its original condition and created 50 dead zones
in the world’s oceans.
-
A single
species -- Mankind -- has more impact on habitat degradation throughout
the globe than all other species combined. Read
Mel Otten's article about the five primary processes
of degradation: over harvesting, alien species introduction,
habitat fragmentation, pollution and outright habit
destruction.
- Desertification
is one result in this prototypical "tragedy of the commons:"
Rising sands are part of a new desert forming on the eastern edge of
the Qinghai-Tibet Plateau, a legendary stretch once known for grasses
reaching as high as a horse's belly and home for centuries to ethnic
Tibetan herders.
In
the News
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