Page 41 - Science Coursebook

2.9 Protecting the environment

Questions

You will need to think about your work on ozone depletion in Stage 7 to answer
these questions.
2 What is ozone, and where is the ozone layer?
3 Why is the ozone layer important to us?
A+I 4 Look at the graph on the previous page. Suggest why CFC levels began to rise
in the 1950s.
A+I 5 Suggest why the level of CFCs did not begin to fall until after 2000, even

though the international treaty to reduce CFCs first came into force in 1989.
Reducing carbon dioxide emissions
Countries have signed international treaties
promising to reduce the amount of carbon
dioxide they produce. However, this has proved

very difficult to achieve. Most countries have not
managed to meet the targets for reducing carbon
dioxide emissions.
This means that carbon dioxide concentrations
in the atmosphere are still rising. This is causing
the Earth to get warmer. This is called global
warming.

Global warming will affect the habitats of many

different species. Species that are adapted to live
in cold places will have to move, or they may
become extinct.

Polar bears need to hunt on sea ice to find seals, their

Global warming affects climate patterns. Some main prey. Global warming may cause much of the
countries will get less rainfall than they do now. sea ice in the Arctic to disappear.

Others may get more. This may make it difficult

for people to grow their usual crops. It could also
change the habitats of plant and animal species.
Question

A+I 6 Suggest why it has proved to be so difficult for countries to reduce their
carbon dioxide emissions. (You will need to think about where the carbon
dioxide comes from.)

Summary
• Nations all over the world are acting together to try to reduce the
harm we do to the environment.
• The Ramsar Convention has helped to save many wetlands.
• There has been great success in reducing CFC emissions.

• It is proving very difficult to reduce carbon dioxide emissions.

2 Living things in their environment 39