The
Earth is very fragile and it is important that we look
after it. The Earth summits bring people together from
all over the world to discuss ways in which we can tackle
problems.
Over the past 100
years the world has been getting warmer and warmer.
One of the reasons for this is the burning of more
and more fossil fuels such as coal and gas. These
give off carbon dioxide, a gas which acts as an invisible
blanket and traps the heat which would normally escape
into space.
Another problem are man-made chemicals known as CFCs,
which were often found in fridges and spray cans. Although
they've been banned for over 20 years, they have
affected the ozone layer around the Earth which protects
us from the harmful rays from the sun.
Both problems have caused an increase
in what is called the greenhouse effect.
Scientists are worried that the
rise in temperature of the sea will cause the water
to expand. This would mean a rise in sea level and
flooding over large areas. |
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Fig 1: Birds wearing gas masks. |
Air pollution
Acid rain is rain that contains gases,
soot and dirt. The burning of fossil fuels adds acid to
the rain which already contains some because of the carbon
dioxide.
Acid rain can cause a lot of damage to
plants and buildings.
Events such as the burning of oil wells
in the Gulf War also pollute the air.
Scientists are working on new ways of
producing energy which do not produce polluting gases,
e.g. wind, wave and solar power.
In some cities around the world exhaust
fumes from cars produce a lot of pollution, which often
produces a haze known as 'smog'.
Let's find out
Find out what you can about alternative
sources of energy such as wind turbines and solar power.
How useful will these be?
People are worried about the destruction
of the rain forests in many parts of the world. Why?
How can you help to improve the world
that you leave in?
What do you think the weather will
be like in the UK in 80 years' time?
Things to make
You will need:
- a plastic bottle;
- scissors;
- coffee filter paper.
Cut the bottle in half and reverse
the top to make a funnel.
Put the filter paper in the funnel
and put the bottle out in the open.
Examine the paper after it has
rained. Can you see flecks of dirt on the paper? How
clean is your rain? |
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Fig 2: A plastic raingauge. |
Amazing facts
Every minute of every day, an area of
tropical rain forest the size of 200 football pitches is
destroyed.
In 1883 a volcano called Krakatoa, Indonesia
erupted. Some 25 cubic kilometres of rock, ash and pumice
were ejected into the atmosphere. Dust from the eruption
stayed in the atmosphere for more than three years, producing
many spectacular and colourful sunsets.
By destroying the rain forests we are
destroying the homes of birds and other animals because the
rain forests are home to more than half the world's
animals and plant species.
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Fig 3: Bird
leaving home. |
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