Our Environment

How do we impact our environmental systems? How do peoples actions affect the environment? Are we slowly hurting our planet?

Human activities can affect the quality and supply of renewable resources such as land, forests, fisheries, air, and fresh water.

What is the key?

Sustainable Development

Sustainability: a way of using natural resources without depleting them while providing for human needs without causing long term environmental harm.

What are renewable and nonrenewable resources?

Sustainable Development

Renewable Resources: resources that can regenerate if they are living or can be replenished by biochemical cycles if they are nonliving.

Trees Water Oxygen Foods (fruits and vegetables, meat from animals)

Nonrenewable Resources: resources that cannot be replenished by natural processes.

Fossil fuels (coal, oil, gas) Minerals (copper)

Renewable Resources

Less Destruction of Earth (we don’t always need to drill into the planet)

Less Pollution (cleaner forms of energy like air and water)

Costs Less (sunlight is free the last time I checked)

Alternative Forms of Energy (solar, wind, geothermal)

Nonrenewable Resources

The Other BIG 3 Coal (creates pollution and smog)

Oil (can get expensive……..glad I don’t drive a Hummer)

Natural Gas (Used to cook and heat homes but not easily transported)

The problem with the big 3:

Time….we just don’t have enough of it!!!

Our impact on the Environment

Soil Erosion: the wearing away of surface soil by water and wind.We add to this with the removal of trees (roots hold soil together)

Desertification: when farming, overgrazing, and drought combine to turn once productive areas into deserts (usually happens in areas with dry climates)

Deforestation: loss of forests (who do you think is guilty of this?)

Overfishing: harvesting fish faster than they can be replaced by reproduction.

What can we do?

Sustainability

Proper management of soilHumans need to control grazing and use proper farming

techniques

ReforestationReplanting trees and controlling the rate at which we cut down

timber

Fishing GuidelinesObeying the laws against catching fish that are protected

(including size and “out of season” factors)

Pollution

Destruction of the Ozone Layer The use of CFCs (chlorofluorocarbons use as propellants in

aerosols and refrigerants. Water vapor (water vapor suppresses the formation of ozone)

What can we do?Banning CFCs In 1987, 46 nations signed an agreement called the Montreal

Protocol. It called for the immediate reduction of CFCs. The U.S. phased out the use of CFCs in aerosol cans by the year 2000.

Reduce, Reuse, Recycle

Biodiversity

Biodiversity: the sum total of genetically based variety of all organisms in the biosphere.

Ecosystem Diversity: the variety of habitats, communities, and ecological processes in the biosphere.

Species Diversity: the number of different species in the biosphere.

Genetic Diversity: the sum total of all the different forms of genetic information carried by all organisms in the biosphere.

What does all this mean to us?

Biodiversity

Biodiversity is one of Earth’s greatest natural resources. Species of many kinds have provided us with:

Foods Industrial products Medicines Painkillers Antibiotics Heart Medicines Antidepressants Anticancer Drugs

Threats to Biodiversity

Human activity can reduce biodiversity by: Altering habitats (new construction by man means new home for wildlife)

Sometimes moving away spells the vanishing of the species.

Hunting species to extinction (Gorillas, Tigers, Jaguars, Eagles) Sometimes other activities also endanger the species. We don’t hunt Pandas but we deprive them of adequate bamboo. We don’t hunt Panthers but our close proximity puts them in danger.

Introducing toxins into food webs (DDT was a pesticide used to kill insects in agriculture. Cheap to use and was long lasting. The problem: it’s not biodegradable and aquatic plants can’t eliminate it from their tissue.

Introducing foreign species into new environments(invasive species reproduce quickly and take over because their regular predators are absent. This takes away equilibrium from any ecosystem.

Conserving our Biodiversity

Conservation: the wise management of natural resources, including the preservation of habitats and wildlife.

Zoos (breeding animals to later release them to the wild) Marine Sanctuaries (protect our coral reefs and marine

mammals) Wildlife Reserves (Lacey Act of 1990: transporting of

illegally killed animals becomes federal crime)

A Healthy BiosphereOur society depends on a healthy biosphere. We need our

biosphere to be healthy, diverse, and productive because we gain environmental and economic benefits.

Global Warming

All life on Earth depends on climate conditions such as temperature and rainfall. That's why many ecologists are concerned about strong evidence that climate is changing.

Since the late nineteenth century, average atmospheric temperatures on Earth's surface have risen about 0.6 Celsius degrees.

The term used to describe this increase in the average temperature of the biosphere is Global Warming.

Global Warming

It’s suggested that in 50 years the remaining ice will be gone!

Global Warming

The controversy!

Is this trend due to a larger, natural cycle of climate change or are we responsible for this?

What does the evidence say?The most widely accepted hypothesis is that current warming is

related, at least in part, to human activities that are adding carbon dioxide and other greenhouse gases to the atmosphere.

According to this hypothesis, the burning of fossil fuels, combined with the cutting and burning of forests worldwide, is adding carbon dioxide to the atmosphere faster than the carbon cycle removes it.

Possible Effects of Global Warming 

Most recent computer models suggest that average global surface temperatures will increase by 1 to 2 Celsius degrees by the year 2050.

What does this mean to us?

Sea levels may rise enough to flood some coastal areas. Flooding would affect coastal ecosystems as well as human

communities. More droughts during the summer growing season. New organisms may be able to live in places where they once

could not. Other organisms may become threatened or extinct.

Let’s see how you’re doing

1. A large area of farmland has many different species of insects living on it. Most of these insects are pollinators of the crops that grow on the farm. If Ms. Robinson decides to plant one crop on all her plots, what will be the result?

A. There will be less insect diversity.B. The crops will be more likely to survive.C. The crops will undergo genetic mutations.D. The different insect species will interbreed.

Keep it up

2. A great deal of research is being done to make plastic wastes useful by reusing the plastic for purposes other than the plastic's original use. Which statement below best describes the impact reusing, rather than recycling, plastics might have on our environment?

A. Natural resources can be conserved or made available for other uses.

B. More plastic will have to be produced to make up for the lost plastic reused for something else.

C. Landfills will have new materials to dispose of, making the present systems of disposing wastes obsolete.

D. The new plastic materials will be every bit as nondegradable as the plastics they were made from, causing large amounts of wastes.

Did I mention that I like your smile?

3. Industries often spring up along major rivers, such as the Willamette in Central Oregon. Some of these industries used PCBs (toxic, cancer-causing chemicals), which are not biodegradable. If PCBs escaped into the river in large amounts and entered the lower levels of the food chain, what would be the likely outcome?

A. All species, except scavengers such as riparian crustaceans, would be harmed by the PCBs.

B. Only the small fish and crustaceans that are most exposed to the PCBs would be significantly harmed.

C. Over time, PCBs would collect in top predators such as salmon, making them unsafe for human consumption.

D. The PCBs would become harmless as they break down over time with exposure to the forces of nature and the environment.

Just a few more

4. An isolated community has a sunny climate with intermittent winds. It is not located near the ocean or a large river. It wants to switch to a renewable source of energy that creates the least air or water pollution. Which energy source should they choose?

A. biofuelB. hydroelectricC. nuclearD. solar

I’m so proud of you.

5. In the early twentieth century, kudzu (an Asian vine) was planted to help control erosion in southeastern states. Presently, kudzu is expanding at a rate of more than 120,000 acres per year. As kudzu spreads, it dominates ecosystems, choking out trees and other plants. Which choice correctly identifies kudzu’s role in an ecosystem?

A. invasive speciesB. diversified speciesC. indigenous speciesD. carnivorous species

Last One……Almost

6. A team of scientists and Ms. Villalobos were studying glaciers in Greenland and found that in the late 1900s a particular glacier on Greenland's west coast started moving faster toward the sea, melting more, and thinning. These changes are attributed to the warming period Earth has been experiencing over the last 100 years. If this warming trend continues, what could result?

A. a significant rise in sea levelB. an increase in the ocean's salt contentC. a significant decrease in ocean water temperatureD. the presence of icebergs farther from the polar caps

Last One!

7. The number of pythons found throughout Everglades National Park has increased in recent years. These huge snakes are not native to Florida and are believed to have been released into the wild by pet owners. Wildlife biologists have initiated attempts to capture and remove these pythons. Which statement best explains the biologists’ reason for removing these pythons from the Everglades?

A. The pythons could upset the territorial boundaries of native organisms.

B. The pythons could adapt to overcome diseases common to native snakes.

C. The pythons could prey on native organisms and cause native populations to decline.

D. The pythons could begin to interbreed with native snakes and produce a more successful species.

The End

Answer Key

1. A2. A3. C4. D5. A6. A7. C