PollutionPollution

Humans need to be responsible

for their environment and learn

to work with nature

OutlineOutline1. Key concepts

2. The biosphere

3. Nonrenewable resources

4. Renewable resources

5. Solid waste

6. Surface water and ground water

7. Air pollutions: pollutants, smog, acid rain

8. The greenhouse effect

9. The ozone layer

10. Conclusions

Key Concepts:Key Concepts:

1. Human population growth has been

increasing

2. Adaptive mechanisms are not in place to

handle pollutants

3. Many pollutants exert regionally harmful

effects

Key Concepts:Key Concepts:

4. Deforestation and land conversion for

agriculture meeting the demand of growing

human population are leading to loss of soil

fertility and ecosystem balance

5. A decline in the quality and quantity of water is

occurring

6. Human activities are disrupting interactions in

ways that may have severe consequences

The biosphereThe biosphere

• Biosphere: global ecosystem encompassing all other ecosystems

• Thin region (only 20,000 meters or ~12 miles thick) capable of sustaining all life on Earth

� extends from approximately 9000 meters above sea level to about 11,000 meters below sea level

• Synonym: “the environment”

The biosphereThe biosphere

Nonrenewable resourcesNonrenewable resources

All resources come from the land

Nonrenewable resources: formed at a rate much slower than their consumption; coal, oil, minerals--once used up, they’re gone!

Includes fossil fuels, uranium, wood, and minerals (iron, aluminum, copper, zinc)

Recycling and reuse conserve resources and reduce waste disposal

Nonrenewable resourcesNonrenewable resources

Ιn agricultural ecosystems, a large amount of nutrients are removed from the area in the crop biomass.

After awhile, the natural store of nutrients can become exhausted.

Renewable resourcesRenewable resources

Produced by natural systems: nonfinite; replace themselves quickly enough to keep pace with consumption

• Solar power

• Hydroelectric power

• Wind

• Geothermal energy

• Biologically produced fuel gases

Solid wasteSolid waste

Garbage produced in large quantities in industrialized world must be deposited in landfills or burned: neither option good!

Many landfills running out of space or are polluted or dangerous; must be closed

Alternatives include:

� better planning for waste disposal

� reduce = less consumption; recycle/re-use;

Surface water and ground waterSurface water and ground water

Pollution from many sources

Point sources: factories, sewage treatment plants, etc.

Nonpoint sources:� Runoff of sediments caused by erosion, etc.

� Metals, acids from mines

� Poisons from hazardous waste dumps

� Pesticides/herbicides/fertilizers from treated agricultural land after rain

Surface water and ground waterSurface water and ground water

Water pollutants may not be removable and can kill plants and animals� Nutrients: excess cause eutrophication of

surface waters, death of fish, etc.

� Toxins: may accumulate in food chain

� Thermal pollution: heated water kills plants, fish

• Prevention of pollution is more effective than cleanup

Surface water and ground waterSurface water and ground water

Air PollutantsAir Pollutants

1.Carbon oxides CO, CO2

2. Sulfur oxides SO2, SO3

3.Nitrogen oxides NO, NO2, N2O

4.Other organic CH4, CFC’s,

compounds

5.Suspended particles Dust, soot, lead,

pesticides

Regional Differences in Regional Differences in Concentrations of Fine ParticlesConcentrations of Fine Particles

Smog

Acid RainsAcid Rains

• Acid rain: rainwater acidified by sulfuric and nitric acids formed by discharge of industrial chemicals

• Acidification kills fish, plants,and microorganisms; alters ecosystem

� leaches poisonous materials (and essential minerals) out of soil into surface and groundwater

� eats away stone, paint, metal

� damages symbiotic associations

Acid DepositionAcid DepositionDry Acid and Acid rainDry Acid and Acid rain

Sulfur and

nitrogen oxides

Coal burning

power plants

Factories

Vehicles

Fertilizers

Greenhouse Gases and a Warmer Greenhouse Gases and a Warmer Planet Planet

Greenhouse effect

1. Rise sea level

2. Change rainfall patterns

3. Change ocean currents

4. Change species composition

5. Change growing conditions

CO2, Ozone, Methane, Nitrous oxide, CFC’s

Fossil fuel burning and deforestation

contribute to increases in global warming

Global WarmingGlobal Warming

Atmospheric CO2

Glaciation and Interglacial Periods

From Greenhouse Gases to a From Greenhouse Gases to a Warmer PlanetWarmer Planet??

Greenhouse effect

Increase in CO2

Increase in CFC’s

From Greenhouse Gases to a From Greenhouse Gases to a Warmer PlanetWarmer Planet ??

Greenhouse effect

Increase in nitrous oxide

The ozone layerThe ozone layer• Ozone being destroyed where needed most,

in the stratosphere (layer of the atmosphere directly above the biosphere)

� ozone forms when sunlight reacts with oxygen

� acts as a shield against sun’s ultraviolet (UV) rays which can damage cells / cause cancer

• Chlorofluorocarbons (CFC) responsible

• Refrigerators and air conditioning solvents

• International agreement limits release and will cut CFC emissions

Life on earth is protected from the damaging affects of ultraviolet radiation (UV) by a layer of O3,or ozone.

Studies suggest thatthe ozone layer hasbeen gradually“thinning” since 1975.

Human activities are depleting Human activities are depleting

the atmospheric ozonethe atmospheric ozone

Classification of Land Suitability for Classification of Land Suitability for AgricultureAgriculture

Land UseLand Use

Almost 21 percent of Earth’s land is

used for agriculture or grazing

About half the Earth’s land is

unsuitable for such uses

Remainder could be used, but at a

high ecological cost

Humans and ChangeHumans and Change

Unlike previous species, human

have the capacity to observe and

make decisions about the changes

they bring about

In ConclusionIn Conclusion

1. Accompanying rapid human population growth

is increases in energy demands and pollution

2. Pollutants are substances with which

ecosystems have had no prior evolutionary

experience

3.Smog arises in industrialized and urban regions

that rely on fossil fuels

4.Oxides of sulfur and nitrogen contribute to acid

rain

In ConclusionIn Conclusion5. The thinning of the ozone layer has increased as

CFC’s and other pollutants destroy it

6. Global freshwater supplies are being depleted or

polluted

7. Energy as fossil fuels is nonrenewable and

alternative forms of energy need to be developed

based on renewable sources

8. Humans need to be responsible for their

environment and learn to work with nature

See you later