Global warming

Unit 4

What causes the global warming?

Human activity or a random but

natural phenomenon?

Think about:

When we talk about this problem, we

naturally link it to the use of energy

and the environmental pollution.

But firstly and importantly, energy

makes a great difference to our lives.

What things do we use energy for?

Things that use energy around us or at any other places:

Where does all this energy come from?

From the following pictures, you will know where all this energy comes from.

windmills a coal power station

an oil refinery a nuclear power plant

solar panels a hydro-electric dam

Fossil fuel ( 化石燃料 ) : Ancient animal and plant material below the surface of the earth with a high carbon content, such as coal, oil and natural gas, which can be burnt to produce energy; also known as non-renewable energy because once they are used they have gone forever; they cannot be renewed.

What are fossil fuels?

Sample listsThings that use energy

Sources of energy

Renewable / non-renewablelight

heatingtelevision

cassetteplayervideo

recorder

oilcoal

natural gas

wind (wind power)

sun (solar energy)

renewable

renewable

non-renewable

non-renewable

non-renewable

fridge

stove

washing machine

hair-dryer

water( hydro-electric) renewable

plant waste (biomass energy)

renewable

hot springs or geysers (geothermal energy)

renewable

the sea (tidal energy)

renewable

computer uranium (nuclear energy)

non-renewable

Renewable or non-renewable?√

Renewable or non-renewable?√

Carbon dioxide

coal

oil

natural gas

global warming● ● ● ● ● ● Why?

Fossil Fuel

A greenhouse

A greenhouse

is made of _______

and is used for

growing ________,

especially during

_____ weather.

What is a greenhouse made of and used for?

glass

plants

cold

The air inside is warm because the

glass traps the heat from the sun and

keeps it from escaping. This makes

the greenhouse heat up and so the

plants can grow

throughout the

cold period.

How does a greenhouse work?

Now can you connect global warming

with greenhouse and think of the

relationship between them? Maybe

you can understand why we call

global warming “greenhouse effect”.

Greenhouse effect

The greenhouse effect is a naturally occurring process that aids in heating the Earth's surface and atmosphere. It results from the fact that certain atmospheric gases, such as carbon dioxide, water vapor, and methane, are able to change the energy balance of the planet by absorbing longwave radiation emitted from the Earth's surface. Without the greenhouse effect life on this planet would probably not exist.

“ 低碳生活” (low-carbon life)

“ 低碳生活” (low-carbon life) ，就是指生活作息时所耗用的能量要尽力减少，从而减低碳，特别是二氧化碳的排放量，从而减少对大气的污染，减缓生态恶化，主要是从节电节气和回收三个环节来改变生活细节。

Save energy! Protect the earth!