Lesson 1

Renewable vs Non-renewable resources

Human Population Growth

Biodiversity

Human Impact on Ecosystems

–Atrozine in water (Frogs) – start at 2:30 to 14:30

Need for Awareness / Understanding

•Human activities can create ecological problems.

•Because environmental issues concern many countries and communities, solutions are complicated and require global awareness, cooperation and action!

Our Environment

•Earth has a finite (limited) supply of resources.

•Renewable resources can be replaced / replenished.

•Ex. Trees, Wind and Solar Power, Crops, Fish

–Overuse at an unsustainable rate may cause a renewable resource to disappear. Ex: over fishing the oceans may deplete fish populations faster than they can replenish themselves.

• Nonrenewable (finite) resources cannot be

replaced and can run out forever!

Ex. Fossil fuels (coal, oil, natural gas)

Many scientists are worried about some of

Earth’s finite resources because humans are

d.

•We can help maintain our supply of both renewable and nonrenewable resources by reducing, reusing and recycling them.

Reduce: turn off the faucet while brushing teeth, buy items in bulk to reduce packing material waste

Reuse: use reusable shopping bags & water bottles instead of disposable ones, use hand-me-down items

Recycle: repurposing of materials as something else! (ex. paper, plastic, metal, glass)

Landfill in Accra (Ghana). We pay developing countries to

take our toxic electrical garbage.

This young boy spends his mornings searching through pollution for

recyclable plastics his family can sell for 35 cents per kilo.

Human Population Growth

• Humans are exceeding the carrying capacity of the earth

(overpopulation)

As a result, humans have negatively impacted the world’s

biodiversity – the variety of living organisms on Earth

a.

Biodiversity is important because…

• Ecosystems with HIGH biodiversity are MORE stable and likely to survive environment changes

• Ecosystems with LOW biodiversity are not as stable and are LESS able to withstand changes to their environment.

• Loss of species with possible medicinal value

–A –B

Which is a healthier ecosystem?

A – it has more

biodiversity!

Threats to Biodiversity

• Changes made by humans can threaten biodiversity. Populations of organisms may decrease to become

Threatened – vulnerable to endangerment in the near future

Endangered – species seriously at risk of extinction

Extinct – no living members of a species are left

Lesson 2

Negative Human Impacts

1- Deforestation & poor land use

2- overharvesting / overhunting

3- Exploitation of wildlife

4- Invasive / Imported species

5- Water Pollution

1. Deforestation & Poor Land Use

• Cutting down trees for paper, lumber, building, & farming leads to habitat destruction, reduced biodiversity, erosion, less oxygen and more carbon dioxide.

• Failing to rotate crops depletes soil nutrients.

1. Deforestation & Poor Land Use (cont.)

• Soil acidification – nitrogen from excess animal wastes (feces) increases soil acidity.

Deforestation Alternative: ex. Shade-grown Coffee

Shade grown coffee benefits song birds who use the coffee plant as a natural habitat, reduces the need for fertilizers & herbicides, and promotes biodiversity!

a.

b.

c.

d.

a.

b.

c.

d.

a.

b.

c.

d.

C

A

C

2. Overharvesting / Overhunting

• Direct harvesting is the removal of organisms from their natural habitat.

• Ex. Fishing, hunting, harvesting plants

3. Exploitation of Wildlife

• Poaching - Illegal hunting or trapping of animals.

• Reduces biodiversity and increases risk of endangerment & extinctions.

Ex. Coral is damaged by beach goers & harvested for aquariums, elephants killed for ivory in tusks, rhinos killed for horns as symbol of status/wealth

4. Imported / Invasive Species

• Biodiversity is reduced when humans import species into new environments, intentionally or not.

• Non-native or invasive organisms disrupt the natural food web, have no natural predators, can out compete native species for resources

How are they imported? -Pet trade

-Attached to ships

-On imported plants Snakehead fish video (3:38 total)

Ex. Asian Long Horned Beetles

• Arrived in wood pallets from China

• Threaten native hardwood trees

Ex. Zebra Mussels

• Feed on plankton & bacteria, disrupting the food web for native species of the Great Lakes

• Introduced from ballast water of ocean going ships

Ex. Purple Loosestrife

• Plant from Europe, Asia, Africa, Australia

• Disrupts water flow in rivers

• Crowds out native cattail plants

5. Water Pollution • Toxic Wastes are poisonous chemicals

dumped into waterways from cities,

farms or industries.

• Ex. chemical fertilizers, pesticides from

farms (DDT), PCB’s & heavy metals like

lead & mercury from factories

• Low levels of these chemicals in the

water increase as they work their way

up the food chain through

biomagnification / bioaccumulation

Video: Symptoms of Mercury Poisoning (The Drs.) 2:30

Ex 1. - introducing the tree swallow (bird), a natural predator of the mosquito to reduce mosquito populations

Ex. 2– sex hormones can attract and trap pests

Biological Controls

• Can decrease pesticide use and limit the chemicals’ impact on the ecosystem and other organisms

• Excess nitrogen from fertilizers produces run off into rivers & lakes, speeding up growth of algae (algal bloom)

• Supply of oxygen is depleted due to overgrowth of algae

• Organisms die

Eutrophication

River

Pipe pouring wastewater into the Yangtze river in China.

Developed countries have wastewater treatment plants to

assist in treating the feces contaminated water.

• Thermal Pollution- Power plants dump hot water that was used to cool nuclear reactors, into lakes which decreases dissolved oxygen & kills aquatic life!

Lesson 3 Negative Impacts (cont.)

6- Air Pollution

7- Global Atmospheric Change

A- Global Warming

B- Ozone Depletion

Ecological Alternatives

6. Air Pollution

• Air Pollution - When fossil fuels are burned by factories, cars, and electrical power-generating plants, sulfur dioxide and nitrogen oxide are released into the atmosphere.

• These compounds released from smokestacks combine with moisture in the atmosphere to form Acid Rain /Precipitation.

- has an acidic pH (below pH of 6) that harms plant life

and organisms in lakes and ponds by disrupting

enzyme function in their cells

• Smog – smoky fog produced by excessive burning of

fossil fuels, harmful to breathe in

Pollution in

Hong Kong is

so bad they

have a fake

skyline for

tourists to

take pictures

with.

7. Global Atmospheric Change A. Global Warming- Greenhouse Gases in the atmosphere

(mostly carbon dioxide from burning fossil fuels) trap heat that normally would radiate into space.

• This excess heat can melt the polar ice caps, affect sea levels, endanger species and disrupt climates!

• Greenhouse Effect Video (2:14)

Sources of Carbon Dioxide (CO2)

Cars burning gasoline

Generating Energy

(Combustion)

Respiration/ Decay

Burning Forests/ Deforestation

–Debate - Bill Nye vs Meterologist Joe Bastardi (6:52 total)

B. Ozone Depletion- The Ozone Shield that protects us from the sun’s UV radiation is being destroyed by man made gases released into the atmosphere.

(Chlorofluorocarbons (CFCs) from air conditioning, refrigeration, aerosol spray cans)

Results? - Increased mutations / skin cancers, Destruction of plankton / algae (which make most of our oxygen!), crop disturbance

Individual Choice and Societal Actions

• Technology can help and hurt the environment.

• To solve some environmental problems, trade-offs must be made. (We must give up one thing to get another)

• We must study the impact of new technologies before we use them.

• Our decisions today will affect future generations!

1. Recycle, use less water, carpool, etc.

2. Replenish renewable resources (reforestation!)

3. Use “shade grown” method for farming!

4. Increase jobs in green technology!

5. Make laws protecting organisms and land from hunting or development.

6. More stringent emissions tests!

7. State/government rewards for organic farmers!

8. Increase funding for public transportation!

9. Introduce a natural predator (biological control) instead of using pesticides!

10. Educate developing countries about conservation! Get them involved!

11. Zoo outreach programs to inform the public about conservation!

What can we do to help? - Match these statements to the problems they may

help (next page).

Ecological Alternatives

2. Replenish renewable resources (reforestation!)

5. Make laws protecting organisms and land from hunting or development

11. Zoo outreach programs to inform the public about conservation!

10. Educate developing countries about conservation! Get them involved!

3. Use “shade grown” method for farming!

1. Recycle, use less water, carpool, etc.

6. More stringent emissions tests!

9. Introduce a natural predator (biological control) instead of using pesticides!

4. Increase jobs in green technology!

8. Increase funding for public transportation!

1. Recycle, use less water, carpool, etc.

1. Recycle, use less water, carpool, etc.

7. State/government rewards for organic farmers!

Practice Questions!

The creation of wildlife refuges and the enforcement of game laws are conservation measures that promote increased 1. use of biocides 2. preservation of species 3. use of biological controls 4. exploitation of species

An example of a biological control against insects is the use of 1. herbicides 2. wildlife refuges 3. pesticides 4. sex hormones

If excessive amounts of hot water are discharged into a lake, the immediate result will most likely be

1. an increase in the sewage content of the lake

2. a decrease in the amount of dissolved oxygen in the lake 3. an increase in the amount of PCB pollution in the lake 4. a decrease in the amount of phosphates in the lake

Over the past few decades, many oil companies have discovered oil

below the seafloor near the coasts of many states. Some states,

however, refuse to permit offshore oil drilling, fearing it might

damage the environment. Discuss both sides of this issue. In your

answer, be sure to:

• state one way in which offshore oil drilling might have a long-

term negative effect on the environment

• state one way in which offshore oil drilling could benefit society

Sample answers:

• Negative – damage to habitats of ocean organisms - causes

water pollution from spills - kill marine life - endanger species

• Benefit - use domestic rather than foreign source of oil - create

jobs - keep prices low - increase the oil supply