Download Biodiversity Loss

Causes of
Biodiversity Loss
Environmental Resource
Management
Development
• As population grows,
landscape changes
• Settlements are growing into
megacities
• Land uses are changed
• Rivers are dammed or diverted
• Modern agriculture & forestry
techniques displace plants
Biotechnology
• Humans are now breeding new
species in a lab
• Some new breeds of plants
and animals have been helpful
• Scientists now creating new
life forms with unknown effects
• New species modify habitats
and destroy other species
• Research is expensive
Genetic Modification
• The total area of land around
the world sown with
genetically engineered crops
increased 25 times between
1996 and 2000. A dramatic
slowdown of this rate from
40% to 11% in between 1999
and 2000 may reflect public
concern about the risks of
these crops.
Use of Fossil Fuels
• Combustion of oil, natural gas,
coal, and by-products like
propane and gasoline pollute
the air and increase the
greenhouse effect
• CO2 content has increased
more than 30% and methane
content has increase 145%
since pre-industrial times
Use of Fossil Fuels
Pollution
• Wastes, gases, and toxic
chemicals from industry,
energy production, sewage,
fertilizers, transportation, and
pesticides contaminate the air,
soil, and water resources
• Contaminants are absorbed
into the plants and animals
• We then eat those species!
Exploitation
• Commercial and recreation
(fishing and hunting) overkill
of a species
• Public demand for tropical
hardwoods remains high
• Some animals seen as vermin
or a threat, some used for
“alternative medicine”
Poverty
• Globalization puts pressure on
countries to build their
economies – at the expense of
their environments
• National debts in developing
countries are often paid by
clear cutting or cash crops
• Local dependence on the land
is therefore even harder
“UN Environment Chief
Targets Poverty”
• UNEP says the rich world is not
doing enough to make
sustainable development a
realistic goal for every country.
• "The fundamental constraint to
achieving sustainable
development is social
inequality and its associated
evils: poverty and ignorance."
Bio-invasion
• Invasive species are ones that
are not native to a particular
ecosystem
• Pose threats to native species
through competition for food
• Some “hitchhike”, others are
intentionally introduced
• “Introductions, like extinctions,
are forever.” Ellen Marsden
Life Out of Bounds
• “Bioinvasion – the spread of
alien, "exotic" organisms – is
gnawing away at ecosystems
all over the world, largely
unnoticed and unopposed.
• “The continuing increase in
travel and trade around the
globe is fostering the spread of
more and more invaders of
almost every conceivable
description.”
Policies
• Governments want to
encourage development, but
are not ecologically based
• Lack of property rights and
corrupt governments mean
less interest in taking care of
the resources
• Effective environmental
protection laws are scarce
Policies
So, for final exam review the
following with regard to Causes
of Biodiversity Loss of Natural
Resources
• Development
• Biotechnology
• Use of Fossil Fuels
• Pollution
• Exploitation
• Poverty
• Bio-invasion
• Policies