earth’s human carrying technology has helped...
TRANSCRIPT
• Earth’s human carrying capacity is unknown
• Technology has helped to increase Earth’s carrying capacity.
– gas-powered farm equipment
– medical advancements – clean water – public assistance
2
• Over 6.6 billion people • Many natural resources are
nonrenewable – Fossil fuels take millions of
years to form
• More people means: – 1) More forests removed – 2) More resources consumed – 3) More CO2 released
3
• Nonrenewable resources are used faster than they can form or be replenished:
– Coal
– Oil
– Natural Gas
• Renewable resources cannot be used up or can replenish themselves over time :
– Wind
– Solar
– Water
MUST BE MANAGED
EFFECTIVELY!!!
4
• The growing human population puts pressure on Earth’s
natural resources
Ecological Footprint • Defined: the amount of
land needed to support a person.
• The land must produce and maintain enough
– food and water – shelter – energy – waste
• Several factors effect size: – Amount/efficiency of
resource used – Amount/toxicity of
waste produced 5
Ozone Layer Depletion • Ozone Function: Block UV radiation from sun
• Cause: – CFCs (air pollution) thin
the ozone layer – More UV radiation
reaches the surface
• Effects: – Crop damage – Skin cancers – Eye damage
• Solution: – Reduce/Regulate CFCs – Plant trees
UV
Ozone layer Ozone layer
CFCs
UV
7
Smog and Ground-Level Ozone • Causes:
– Burning of fossil fuels & industry
• Particulates rise into air and react with sunlight to make air pollution
• Effects:
– Ozone gas (O3)is poisonous
– Respiratory illness
• Solutions:
– Reduce use of fossil fuels
– Alternative energy sources
– Plant trees
8
The Greenhouse Effect • G.H.E. is naturally good (it
warms Earth)
• Causes: CO2 from burning of fossil fuels (coal, oil, natural gas)
• Effects: Excess heat trapped near the earth’s surface may change global climate patterns; ice caps melt
• Solutions: Reduce use of fossil fuels, plant trees, alternative energy sources
9
What’s a Greenhouse? A Greenhouse is
designed to trap
heat so you can
grow plants year
round, even in
cooler
environments.
Some heat
escapes the
greenhouse,
but enough is
trapped to
keep the
inside warm
Earth
Some heat
escapes into
space Some heat
naturally trapped
by CO2 and other
greenhouse
gases
The Natural Greenhouse
Effect is good for life on
Earth.
CO2
CO2
CO2
CO2
CO2
CO2
CO2
CO2
CO2 CO2
CO2
CO2
heat
Earth
Excess CO2
in
atmosphere
Less heat
escapes into
space
More heat trapped
near Earth’s
surface
CO2
CO2
CO2
CO2
CO2
CO2
CO2
CO2
CO2 CO2
CO2
CO2
CO2
CO2 CO2
CO2
CO2 CO2
CO2
CO2
CO2
CO2
CO2
CO2
CO2
CO2
CO2
heat
The Greenhouse Effect is naturally GOOD!
Mars: No Greenhouse Effect
Little heat is trapped by the thin CO2 atmosphere. High temperatures can be around 20⁰F.
Earth: Balanced Greenhouse Effect
Average global temperature is 57⁰F.
Venus: The Extreme Greenhouse Effect
Heat is trapped by the thick CO2 atmosphere. Temperatures reach 750⁰F.
14
• Defined: Precipitation with a below normal pH
• Cause:
– Fossil fuel pollution rises into the air & then falls as rain
• Effects:
– Waterways more acidic
– Kills plant and animal life
• Solutions:
– Reduce fossil fuel usage
– Add buffer (base) to waterways
15
• Defined: pollution in water supplies
• Causes:
– Waste
– Medicines
– Agricultural Runoff
– fertilizers
– pesticides
• Problems:
– Species lost
– Ecosystems harmed
• Solutions:
– Manage waste 19
• Indicator species: Give sign of ecosystem’s health
• Example:
• Amphibians
• Frogs are good indicator species because their skin is water permeable.
• Top predators
• Solution: Waste Management 20
• Defined: Accumulation of toxins in the food chain
• Fat soluble pollutants move up food chain.
– These pollutants stay in the body fat of an organism
– Predators eat contaminated prey
– Pollution accumulates at each level of the food chain
• Top consumers, including humans, are most affected.
21
Deforestation • Defined: Clearing of
forested areas
• Causes: Harvesting/destroying forests for high demand:
– Wood products
– Creating farmland
• Effects:
– Species lost
– Excess CO2 released
• Solutions:
– Recycle
– Improved farming techniques 22
Introduced & Invasive Species • Defined: Foreign organisms are
introduced to a new habitat – Invasive: harms native species
• Cause:
– Foreign species introduced to new environment
• Effects:
– Foreign species outcompete native species
– Food webs unbalanced
– Economic damage
• Solutions:
– Laws preventing foreign goods into new countries
– Introduce predators 24
• The Environmental Protection Agency (EPA)
– Created in 1970 – Works to protect species
• Clean Water Act • Clean Air Act • Endangered Species Act
– This recovered the bald eagle – Those listed are called “Umbrella
Species” – Entire habitats protected
25
Review 1) CFCs are manmade chemical responsible for the destruction of the
2) Which gas is a main contributor to the greenhouse effect?
3) Crop damage and cancers are caused by an excess amount of which type of energy? __________________
4) Name the big three fossil fuels:
5) Which planet has excess temperatures because of a thick CO2 atmosphere?
6) What is smog?
7) How are pollutants passed through the food chain?
8) Where is ozone gas harmful to life?
9) Where is ozone gas helpful to life?
10) What makes a resource nonrenewable?
11) Food webs become unbalanced as a result of the introduction of which type of organisms?
12) What is an umbrella species?