Human Impact on the Environment:
Current Crises for Human Survival:
Problems to be Solved Within the Next Generation
Practical observation of ONE example of human influence on the
environment in the local area (e.g. the impact of alien species on
biodiversity). Written report on the chosen example.
Look at the interrelatedness and interdependence of the human
impacts and the environment.
In nature all things are recycled
Humans upset the cycles
More buildings
Food costs
Energy Costs
What
have you
noticed?
Fish
Transport
Weather
Research: Human impact on the environment
Food security
Deforestation
Loss of
Biodiversity
Discuss what
you
understand
these terms
to mean
Climate change
Desertification
The atmosphere and climate change
• carbon dioxide emissions;
• - concept of ‘carbon footprint’ and the need to
reduce the carbon footprint;
• - deforestation;
• - greenhouse effect and global warming:
– desertification, drought and floods;
• - methane emissions;
• - ozone depletion.
http://www.vanderbilt.edu/sustainvu/2009/03/so-what-isa-carbon-footprint-and-why-is-vanderbilt-calculating-one/
Carbon footprint: the amount
of carbon dioxide or other
carbon compounds emitted
into the atmosphere by the
activities of an individual,
company, country.
Brainstorm what
you can do to
reduce your carbon
footprint
Main greenhouse gases:
Carbon dioxide
Water
Methane
http://www.epa.gov/climatechange/kids/basic
s/index.html
•
Desertification is a complex
process involving multiple natural
and human-related causes. In
desertification, the productive
potential of arid and semi-arid
lands falls by 10% or more, and
topsoil is lost or degraded.
– Desertification results mainly
from a combination of natural
climate changes causing
prolonged drought and
unsustainable human activities,
including overgrazing and
deforestation.
– Desertification may lead to the
formation of a desert or the
encroachment of an existing
desert onto formerly arable
land.
Overgrazing on marginal lands (top) can
extend desert zones (lower)
Effects of Climate Change
Effects of Climate Change
Effects of Climate Change
http://www.epa.gov/climatechange/kids/
Research what
individuals, schools,
communities and
businesses can do to
reduce climate change
Most household cleaning
can be done with a half-andhalf mixture of vinegar and
water, or liquid soap
and baking soda.
If it has a
thermostat it
uses a large
amount of
electricity.
How can your
family/school
reduce its
electricity
consumption?
Not all SA’s have
access to safe water.
Investigate how
human activity affects
water quality and
availability and
suggest solutions
Water:Availability:
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Construction of dams
- Destruction of wetlands
- Poor farming practices
- Droughts and floods
- Exotic plantations and depletion of water table
- Boreholes and effects on aquifers
- Wastage
- Cost of water
Water: Quality
• - Water for domestic use, industry, agriculture
and mining: pollution, diseases,
eutrophication and algal bloom.
• - The effect of mining on quality of water
• - Thermal pollution The need for water
purification and recycling
• - Alien plants, e.g., Eichornia
Monoculture
Floods and Droughts
Dams
Boreholes and effects
on ground water
Invasive alien
plants eg
Exotic plantations
Water hyacinth/Eichonia
What is a wetland?
• Wetlands are areas
where terrestrial and
aquatic ecosystems come
together.
• In a wetland, the water
table is at or near the
surface of the ground.
The land is either
temporarily or
permanently covered
with shallow water.
http://wetlands.sanbi.org/
Food security is built on
three pillars:
• Food availability: sufficient
quantities of food available
on a consistent basis.
• Food access: having
sufficient resources to
Think of food
wastage at home/
obtain appropriate foods
school/ shops –
for a nutritious diet.
how can this be
reduced and
• Food use: appropriate use
contribute towards
based on knowledge of
food security for all
basic nutrition and care, as
well as adequate water and
http://www.unwater.org/worldwaterday/hungry_thirsty.html
sanitation.
http://www.who.int/trade/glossary/story028/en/
Food Security
(link with population ecology dynamics)
• human exponential population growth;
• - droughts and floods (climate change);
• - poor farming practices: monoculture; pest
control,
• loss of topsoil and the need for fertilisers;
• - alien plants and reduction of agricultural land;
• - the loss of wild varieties: impact on gene pools;
• - genetically engineered foods;
• - wastage.
Biodiversity is the degree
of variation of life forms
within a given species,
ecosystem, biome, or an
entire planet. Biodiversity is a
measure of the health of
ecosystems. Biodiversity is in
part a function of climate
http://www.novamind.com/connect/nm_documents/285
http://www.novamind.com/connect/nm_documents/285
http://www.eco-question.com/what-are-the-main-causes-of-biodiversity-loss
Loss of Biodiversity (the 6th extinction)
- habitat destruction: farming methods, e.g.,
• overgrazing and monoculture, golf estates, mining,
• urbanisation, deforestation; loss of wetlands and
• grasslands;
- poaching, e.g., for rhino horn, ivory and ‘bush meat’;
- alien plant invasions: control using mechanical, chemical
and biological methods; and
- indigenous knowledge systems and the sustainable use
of the environment e.g., devils’claw, rooibos, fynbos, the
African potato (Hypoxis) and Hoodia.
Loss of Biodiversity (the 6th extinction)
Investigate: Rhino poaching in South Africa: read
articles and make suggestions on how it can be
prevented.
Solid Waste Disposal
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- managing dumpsites for rehabilitation and
prevention of soil and water pollution;
- the need for recycling;
- using methane from dumpsites for domestic
use:
• heating and lighting; and
• - safe disposal of nuclear waste.
Solid Waste Disposal
• Analyse the solid waste generated in the
household in one week, including paper, metals
and plastic.
• Estimate the percentage that could be recycled or
reused.
• Visit a municipal landfill site, or a local refuse
dump. Observe rehabilitation (or lack thereof) in
practice.
• Assess the effectiveness of waste management.
If anything in your dustbin
can be reused by
somebody else, recycled
or repaired it should not
be there!
Waste is Costly
The earth is a closed system.
• Any nutrients and resources being
taken out of the system (and buried
in a landfill, or burnt) are resources
lost to us.
•
To produce one ton of paper, 100 tons of
water are used.
For every litre of beer, 10 litres of water
have been used in the fermenting process.
Producing one cellphone requires 75 kg of
resources.
A toothbrush requires 1,5 kg of resources
– coal, oil and water – for its production
Types of waste
Methane gas from landfill sites to
energy
Benefits of recycling
• reduces the amount of waste going into
landfill sites, saving airspace;
• creates jobs and money for schools and
organisations;
• reduces pollution and litter;
• saves raw materials needed to make new
products;
• reduces the need to import expensive
raw materials;
Benefits of recycling
• slows down the use of the world’s nonrenewable (oil, coal and iron) and
renewable resources (trees);
• reduces energy costs in manufacturing of
containers, packaging, etc.
• saves water (used in packaging and
product manufacture). Recycling paper
uses 50% less water than paper that is
made from wood pulp.