2. INTRODUCTION
Human impact on the environment or
anthropogenic impact on the
environment includes:
Impacts on biophysical environments,
biodiversity &
other resources.
The term anthropogenic describes an
effect or object resulting from human
activity.
3. ENVIRONMENTAL ISSUES IN SA
Many environmental issues affect SA
urbanization & acts (LAWS) needed to survive.
Keeping up with developing world + meet high
demands of growing population, SA
exhausted its many resources severe
environmental damage.
Continuous depleting & improper treatment of
natural resources SA only harming their
environment.
4. HUMAN ACTIVITIES THAT
HAVE AN ENVIRONMETAL
IMPACT:
Agriculture (FARMING)
Fishing
Irrigation
Meat production
Palm oil farming
Energy harvesting and consumption
Coal mining and burning
Manufacturing of products
Electricity generation
The use of fertilisers may cause
eutrophication
5. THE EFFECTS OF HUMAN
INFLUENCES ON THE
ENVIRONMENT
Human impact on biodiversity significant.
Human impact on coral reefs significant. Coral
reefs are dying around the world. Coral reefs also
face high dangers from pollution, diseases,
destructive fishing practices and warming
oceans
Human impact on nitrogen cycle diverse.
Humans destroying habitats & reducing amount
of land available for other organisms by building,
quarrying, farming and dumping waste.
Human activities polluting water, air and land.
9. WATER POLLUTION
Water pollution contamination of water
bodies.
Water pollution pollutants are
discharged directly/indirectly into water
bodies without adequate treatment to
remove harmful compounds.
Water pollution affects plants & organisms
living in these bodies of water.
10. WATER POLLUTION
One of SA biggest issues is the lack of clean
water.
Water around Africa unevenly distributed
meaning that 60% of water situated in only 20% of
land.
<10% of SA surface water is accessible
majority of ground water lay under large rock
formations becomes difficult to access.
Climate change & its related effects on
temperature & precipitation may have an
additional impact.
11. WATER POLLUTION – Coal
Mining
Coal mining one of SA main energy source:
huge negative impact on land’s water, air & soil quality.
Acid mine drainage result of excess coal
mining.
Process to neutralize Sulphuric Acid released
from coal mining extremely slow.
Clean, excess water released from rock
masses that are broken through mining mixed
with sulphuric acid water becomes toxic.
12. WATER POLLUTION – Coal
Mining
Toxic, contaminated water
kills plants & animals,
dissolving aluminium & heavy minerals
found in clean water (increasing toxicity
level).
Rocks which contain calcium carbonate
able to neutralize acidic water,
SA does not have the rocks which contain
these minerals.
13. 2 CATEGORIES OF SOURCES OF
SURFACE WATER POLLUTION
Point source water pollution:
Contaminants that enter waterway from single,
identifiable source, such as a pipe or drain.
Examples of sources:
discharges from sewage treatment
plant,
factory, or
city storm drain.
15. Non–point source pollution (NPS):
Diffused contamination does not
originate from a single discrete source.
Cumulative effect of small amounts of
contaminants gathered from a large area.
Common example: leaching out of nitrogen
compounds from fertilized agricultural
lands.
Nutrient runoff in stormwater from "sheet
flow" over an agricultural field / forest
examples of NPS pollution.
16. SHEET FLOW
An overland flow / downslope movement of
water taking (thin, continuous film over
relatively smooth soil / rock surfaces)
18. Some of the main contributors
to water pollution are:
Factories / Refineries
Waste treatment facilities
Mining
Pesticides, herbicides & fertilizers
Human sewage
Oil spills
Failing septic systems
Soap (washing car)
Oil & antifreeze leaking from cars
Household chemicals
Animal waste
19. IMPACT OF WATER POLLUTION ON
HUMAN HEALTH
Increased incidence (tumours, ulcers) nitrate
pollution.
Increased incidence (skin disorders) contact with
pollutants.
Increased incidence (constipation, diarrhoea,
infections to intestine.
Dangerous effects on growing foetus pregnant
women.
Concentration of pollutants bio- accumulative
pesticides through secondary / tertiary food chain in
case of non-vegetarians.
Still births, abortions and birth of deformed children.
20. HOW YOU CAN HELP TO PREVENT
WATER POLLUTION
Wash car far away from storm water drains
Don’t throw trash, chemicals, solvents into
sewer drains
Inspect your septic system every 3-5 years
Avoid using pesticides & fertilizers that can
run off into water systems
Sweep your driveway instead of hosing it
down
Use non-toxic cleaning materials
Clean up oil / liquid spills with kitty litter &
sweet them up
Don’t wash paint brushes in the sink
21. AIR POLLUTION
What are the sources of air pollution?
Automobile emissions
Tobacco smoke
Combustion of coal
Acid rain
Noise pollution from cars and construction
Power plants
Manufacturing buildings
Large ships
Paint fumes
Aerosol sprays
Wildfires
Nuclear weapons
22. AIR POLLUTION IN SA
SA developing region (low-grade
fuels are used to meet high demands)
for food, energy.
SO2 & CO2 released in air due to
deforestation & growing amount of air
pollution,
air pollutants in the atmosphere are
slowly building up.
23. THE IMPACT OF AIR POLLUTION ON
HUMAN HEALTH
Principally affect the
body's respiratory
system and the
cardiovascular system.
The health effects:
biochemical and
physiological changes
breathing, wheezing,
coughing
aggravation of existing
respiratory and cardiac
conditions
24. HOW YOU CAN HELP TO
PREVENT AIR POLLUTION
Carpool or join a ride share with friends and co-workers
Don’t smoke
Keep your car maintenance up-to-date
If you have to drive, do your errands at one time
Don’t buy products that come in aerosol spray cans
Avoid using lighter fluid when barbecuing outside
When you drive accelerate slowly and use cruise control
Always replace your car’s air filter
Use a push or electric lawnmower rather than a gas-
powered one
Don’t use harsh chemical cleaners that can emit fumes
Inspect your gas appliances and heaters regularly
25.
26. LAND POLLUTION
SELF STUDY
KNOW THE SOURCE OF LAND POLLUTION
KNOW THE IMPACT LAND POLLUTION HAS ON
HUMAN HEALTH
KNOW HOW YOU CAN PREVENT LAND POLLUTION
27. LAND POLLUTION
Land pollution is the deterioration (destruction) of
the earth’s land surfaces, often directly or
indirectly as a result of man’s activities and their
misuse of land resources.
It occurs when waste is not disposed off properly,
or can occur when humans throw chemicals unto
the soil in the form of pesticides, insecticides and
fertilizers during agricultural practices. Exploitation
of minerals (mining activities) has also contributed
to the destruction of the earth’s surface.
29. OZONE DEPLETION
Life on Earth is protected from damaging
effects of UV radiation by a protective
layer of ozone molecules in the
atmosphere.
Satellite studies suggest that the ozone
layer has been gradually thinning since
1975.
31. Destruction of atmospheric ozone
probably results from chlorine-releasing
pollutants such as CFCs produced by
human activity.
32. The “ozone hole” has increased in size as
ozone depletion has increased.
33. Ozone depletion causes DNA damage in plants &
poorer phytoplankton growth
An international agreement signed in 1987 has resulted
in a decrease in ozone depletion:
The Montreal Protocol on Substances that
Deplete the Ozone Layer (a protocol to the
Vienna Convention for the Protection of the Ozone
Layer) is an international treaty designed to
protect the ozone layer by phasing out the
production of numerous substances that are
responsible for ozone depletion.
As a result ozone hole in Antarctica is slowly
recovering.
Climate projections indicate that the ozone layer
will return to 1980 levels between 2050 and
2070.
34.
35. GREENHOUSE EFFECT AND
GLOBAL WARMING
CO2, water vapour & other greenhouse gases
reflect infrared radiation back toward Earth;
greenhouse effect
Important for keeping Earth’s surface at a
habitable temperature.
Due to burning of fossil fuels, other human
activities,
concentration of atmospheric CO2 has been
steadily increasing.
37. Increased levels of atmospheric CO2 are
magnifying the greenhouse effect, which
could cause global warming and climatic
change.
Increasing concentration of atmospheric
CO2 is linked to increasing global
temperature.
Northern coniferous forests and tundra
show the strongest effects of global
warming.
A warming trend would also affect the
geographic distribution of precipitation.
38. Global warming can be slowed by
reducing energy needs and converting
to renewable sources of energy
Stabilizing CO2 emissions will require
an international effort.
39.
40. Why is Global Warming important?
Temperature increases will have
significant impacts on human activities,
including:
where we can live,
what food we can grow,
how and where we can grow food,
and where organisms we consider pests
can thrive.
41. To be prepared for the effects of these
potential impacts we need to know :
how much the Earth is warming,
how long the Earth has been warming,
and what has caused the warming.
Answers to these questions provide us with a
better basis for making decisions related to
issues such as water resources and
agricultural planning.
43. NATIONAL ENVIRONMENTAL ISSSUES
DEFORESTATION
OVERGRAZING
DESERTIFICATION
CROPS
COMMERCIAL FORESTS
WATER TABLE PROBLEMS
MONOCULTURE EFFECTS BIODIVERSITY
DEPOSIT OF TOXIC SUBSTANCES
INTRODUCTION OF INVASIVE ALIEN
SPECIES INTO SOUTH AFRICA
IMPACT ON BIODIVERSITY
CONTROL MECHANISMS
44. DEFORESTATION
Deforestation is the permanent
destruction of indigenous forests and
woodlands.
The term does not include the removal of
industrial forests such as plantations of
gums or pines.
Deforestation has resulted in the
reduction of indigenous forests.
45. HOW DOES DEFORESTATION
OCCUR?
conversion of forests and woodlands to
agricultural land to feed growing numbers
of people;
development of cash crops and cattle
ranching,
commercial logging destroys trees as well
as opening up forests for agriculture;
felling of trees for firewood and building
material;
46. CONSEQUENSES OF
DEFORESTATION
1. Alteration of local and global climates
through disruption of the carbon and
water cycle
2. Soil erosion
3. Silting of water courses, lakes and
dams
4. Extinction of species which depend on
the forest for survival.
5. Desertification
47.
48. OVERGRAZING
Overgrazing occurs when plants are exposed to
intensive grazing for extended periods of time, or
without sufficient recovery periods.
It can be caused by either livestock in poorly
managed agricultural applications, or by
overpopulations of native or non-native wild
animals.
Overgrazing reduces the usefulness,
productivity, and biodiversity of the land and is
one cause of desertification and erosion.
Overgrazing is also seen as a cause of the spread
of invasive species of non-native plants and of
weeds.
49.
50. MONOCULTURE EFFECTS
BIODIVERSITY
Monoculture is the agricultural
practice of producing or growing a
single crop or plant species over a
wide area and for a large number
of consecutive years.
Monocultures can lead to the
quicker spread of diseases, where
a uniform crop is susceptible to a
pathogen.
Therefore decreasing biodiversity.
51. DEPOSIT OF TOXIC SUBSTANCES IN
THE ENVIRONMENT
Humans release many toxic chemicals, into the
environment e.g. Acid mine water
In some cases, harmful substances persist for
long periods in an ecosystem .
One reason toxins are harmful is that they become
more concentrated in successive trophic levels.
Biological magnification concentrates toxins at
higher trophic levels, where biomass is lower.
52. Pesticides such as DDT are subject to biological
magnification in ecosystems.
In the 1960s Rachel Carson brought attention to
the biomagnification of DDT in birds in her book
Silent Spring
53. INTRODUCTION OF INVASIVE ALIEN
SPECIES INTO SOUTH AFRICA
Invasive species, typically introduced to a
new environment by humans, often lack
predators or disease.
In total there are 200 species of plants that
are declared weeds or invaders in South
Africa.
E.G. Eucalyptus species, Port Jackson
willow, Black wattle.
56. OVEREXPLOITATION OF LOCAL
INDIGENOUS RESOURCES
Overexploitation is human harvesting of
wild plants or animals at rates exceeding
the ability of populations of those species
to rebound
Overexploitation by the fishing industry has
greatly reduced populations of some game
fish, such as bluefin tuna
DNA analysis can help conservation
biologists to identify the source of illegally
obtained animal products.
58. Population growth, urbanization and the
unrestricted collection of medicinal plants
from the wild is resulting in an over-
exploitation of natural resources in
southern Africa.
Therefore, the management of traditional
medicinal plant resources has become a
matter of urgency.
59. Problems arising from the exploitation
of natural resources
Deforestation
Desertification
Extinction of species
Forced migration
Soil erosion
Oil depletion
Ozone depletion
Greenhouse gas increase
Extreme energy
Water pollution
Natural hazard/Natural disaster
60. SUSTAINABILITY OF LOCAL
INDIGENOUS RESOURCES IN SOUTH
AFRICA
The concept of sustainability helps ecologists
establish long-term conservation priorities.
Sustainable development is development that
meets the needs of people today without
limiting the ability of future generations to
meet their needs
Sustainable development requires connections
between life sciences, social sciences,
economics, and humanities
61. SOME OF S.A. INDIGENOUS
RESOURCES THAT SHOULD BE
CONSERVED AND SUSTAINED
Devil’s claw
Rooibos
Fynbos
African potato
Hoodia
Pepperbark tree
62. DEVIL’S CLAW
Devil’s claw is an herb.
The botanical name, Harpagophytum, means “hook
plant” in Greek.
The fruit is covered with hooks meant to attach
onto animals in order to spread the seeds.
The roots and tubers of the plant are used to make
medicine.
Devil’s claw is used for “hardening of the arteries"
(atherosclerosis), arthritis, gout, muscle pain
(myalgia), back pain, tendonitis, chest pain,
gastrointestinal (GI) upset or heart burn, fever, and
migraine headache.
64. ROOIBOS
Rooibos is a member of the legume family of plants
growing in South Africa's fynbos.
Traditional medicinal uses of rooibos in South Africa
include alleviating infantile colic, allergies, asthma
and dermatological problems.
The plant is used to make a herbal tea called
rooibos tea.
Rooibos leaves are dried and used to make tea,
though parts of the plant are now used in skin care
formulas as well
65. AFRICAN POTATO
(Hypoxis)
Africa Potato is rich in vitamins.
Boosts energy, improves immune system and helps
to prevent virus infections.
Lowers high blood pressure and blood sugar levels.
Older generations drink it as a herbal tea, creams and
tablet are also made from this plant.
66. HOODIA
Used as an appetite suppressant and for
treating indigestion and small infections
Hoodia is a leafless spiny succulent plant
with medicinal properties.
It grows naturally in South Africa and Namibia.
The flowers smell like rotten meat and are
pollinated mainly by flies.