What is fuel? A fuel is a substance that provides a form of energy. Energy can be in the form of heat, light, electricity, or motion. When fuel is burned.

What is fuel?

• A fuel is a substance that provides a form of energy.

• Energy can be in the form of heat, light, electricity, or motion.

• When fuel is burned it releases energy: this is called combustion.

Fossil fuels

• What is a fossil?• Fossil fuels are the energy-rich substances

formed from the remains of once living organisms.

Three Fossil Fuels:

CoalOil (petroleum)Natural Gas

Nonrenewable resources• Fossil fuels are non-renewable – they are being

used up faster than they are made.• They take a long time to form and could run out.

– What are the three fossil fuels?CoalOilNatural Gas

Quick Review!

Alternative Energy Resources

We need to find alternative energy resources so that we do not use up all of our nonrenewable

resources

Renewable Resources• A renewable resource is constantly being

supplied.• What are some renewable resources?

Solar Energy1. Solar energy – light and heat energy from the

sun2. Solar energy is the source for wind and water

energy.– How?

• Wind – unequal heating of the Earth causes global winds

• Water – sun heats water for evaporation to start the water cycle

Wind1. Can be used to cause turbines to

move and generate electricity2. The least reliable because of

weather

Hydroelectric Power

1. Flowing water causes the turbines to move and generate electricity.

2. The most common and most used.

Biomass fuels1. Biomass fuels are made from organic

materials.Examples include:– Wood– Leaves– Food wastes– Manure

Geothermal Energy1. Heat energy from underground.2. Magma heats up water underground

Protect our Resources

• You have two minutes. Brainstorm some ways we can conserve our nonrenewable resources.

Energy Conservation

• Conservation means to save energy.• Two ways to avoid fuel shortage:1. Find new sources of energy2. Make fuels available last as long as possible

Ways to conserve:

• Walk or ride bike instead of drive• Put on sweater instead of turning on heat• Use fans instead of air conditioning• Use sunlight instead of electric lights• Turn off lights or TV when you leave the room• Recycle!

QuestionsWhat is pollution?

What are some forms of pollution?

Pollution

• Pollutants – harmful substances in the air, water, or soil.

Water Pollution

• How would you feel if you turned on your water faucet and a stream of nice, fresh, bright green water came out?

• Many things can make water unsafe to drink but don’t change its color, taste, or smell.

• Water pollution is anything that has a harmful affect on the water or the living things in the water

Water Pollution

• What types of water can be polluted?– Surface water– Ground water– Even rain!

• Pollution can result from natural causes and human activities

Sources of Water Pollution

• The major sources of water pollution are human wastes, industrial wastes, agricultural chemicals, and runoff from roads.

Water Pollutants

Disease causing

organisms

Pesticides and

fertilizers

Industrial Chemicals

MetalsRadioactive

wastes

Medical and scientific

Disposal sites, Nuclear

power plants

Petroleum products

Human wastes

and Runoff from

livestock pens

Runoff from farms

and golf courses

Factories

Factories, waste

disposal sites

Road runoff, leaking

Underground storagetanks

Human Wastes

• Human wastes can carry bacteria that causes diseases

• Sewage can leak wastes into drinking water• Wastes can also come from farm animals• If you boil water it kills many disease causing

organisms

Industrial Wastes

• Some factories release toxic chemicals into nearby rivers and lakes

• Many power plants, factories, and cars pollute the air – it then falls as acid rain

• Pouring hot water into lakes and rivers can kill living organisms

Water Pollution:

• Agricultural Chemicals– Runoff from farms can carry fertilizers and

pesticides that pollute water

• Runoff from Roads– Oil, gasoline, and salt from cars can runoff the

road to pollute rivers and lakes

Soil Pollution

• Soil can become polluted by– Landfills– People burying hazardous wastes– Polluted ground water

Air Pollution

• Some air pollution is natural (volcanoes, animals), but most is caused by humans

• Factories, cars, and power plants release toxins into the air which create smog and acid rain.

Where are we now?

• We have made new laws to protect our environment, but we still have a ways to go.

• You can do things to help keep our Earth clean*Recycling–Don’t litter–Conserve energy