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Unit 4: AOS 1, KKP 5
Potential Impacts of
Environmental Threats – Land
Degradation, Climate Change,
Introduced Species &
Urbanisation.
Land Degradation
Deterioration in the quality of land, its topsoil,
vegetation and/or water resources, caused
usually by excessive or inappropriate
exploitation and use.
• Deterioration – Can occur from erosion (wind
or water) as well as physical and chemical.
• Inappropriate Exploitation – overgrazing,
wood collection and deforestation., wood
collection and deforestation.
Land Degradation - Impacts
• Land degradation interrupts ecosystems, in
particular nutrient cycling, carbon cycle and
the hydrological cycle.
• Disruptions to ecosystem functions inevitably
diminishes the above and below ground
biodiversity.
Introduced Species
• Introduced species are foreign species (e.g.
roses, blackberries, foxes, wasps, and root rot)
that have arrived accidentally or have been
introduced intentionally.
Introduced Species –
Positive Impacts
• Many introduced species such as crop plants,
farm animals and game animals are
economically beneficial, and others such as
pets (that are managed responsibly) and
ornamental plants are harmless to the
environment.
Introduced Species –
Negative Impacts
• Many of the introduced species to Australia
have become a significant problem to primary
production and/or the natural environment
and are known as pests. Examples of plant
pests include blackberries, gorse, serrated
tussock and Japanese kelp. Examples of
animal pests include foxes, feral cats, and
rabbits.
Climate Change
• Climate includes patterns of temperature,
precipitation, humidity, wind and seasons. "Climate
change" affects more than just a change in the
weather; it refers to seasonal changes over a long
period of time.
• These climate patterns play a fundamental role in
shaping natural ecosystems, and the human economies
and cultures that depend on them. Because so many
systems are tied to climate, a change in climate can
affect many related aspects of where and how people,
plants and animals live, such as food production,
availability and use of water, and health risks.
Climate Change
• A change in the usual timing of rains or
temperatures can affect when plants bloom
and set fruit, when insects hatch or when
streams are their fullest. This can affect
historically synchronized pollination of crops,
food for migrating birds, spawning of fish,
water supplies for drinking and irrigation,
forest health, and more
Climate Change – Impacts Australia
By 2030 Australia will face:
• - A further 1 degree Celsius of warming in
temperatures.
• - Up to 20 per cent more months of drought.
• - Up to 25 per cent increase in days of very
high or extreme fire danger.
• - Increases in storm surges and severe
weather events.
Climate Change – Impacts Victoria
• A rise in sea level will impact coastal settlements,
infrastructure and ecosystems. This will lead to a
huge cost of up to $11 billion. Roads and railways
lines will be impacted by a rising sea level.
• 13 per cent reduction in average surface water
availability in the south of the Murray Darling
Basin as a median outcome by 2030.
• The average annual number of days above 35°C is
likely to increase from 9 days currently
experienced in Melbourne to up to 26 days by
2070 without global action to reduce emissions.
Climate Change – Impacts Victoria
• As the number of very hot days (above 35°C)
increases and heat waves become more frequent,
more people may suffer heat-related illnesses and
death, with the elderly particularly vulnerable.
• Species such as the Mountain Pygmy Possum that
occupy habitat at the highest elevations and in the
coldest environments will have nowhere to retreat
as the climate warms.
• Potential changes in climate may reduce
productivity and output of Victoria's agricultural
industries in the medium to long term.
Urbanisation
• As world populations have expanded over the
past fifty years; there has also been a drift of
people out of the city centres and countryside
into the suburbs. This outward expansion of
cities is called urbanisation.
Urbanisation - Impacts
• The more people in cities mean more houses,
cars and factories leading to more greenhouse
gas emissions and pollution. In addition to
this, instead of natural bush land, we have
concrete, roads with loud traffic, buildings and
manmade parks.
Urbanisation - Impacts
• Concentrated energy use leads to greater air pollution with
significant impact on human health.
• Automobile exhaust produces elevated lead levels in urban
air.
• Urban development can magnify the risk of environmental
hazards such as flash flooding.
• Pollution and physical barriers to root growth promote loss of
urban tree cover.
• Animal populations are inhibited by toxic substances, vehicles,
and the loss of habitat and food sources.