Living in a Greenhouse
Carbon dioxide and other gases given
off by motor vehicles, power stations and factories are collecting
high in the sky. They are forming an 'invisible greenhouse' around
the Earth. If this goes on, world average temperatures could rise
by 4°C sometime this century. If this happens, the ice-sheets
at the North and South Poles will begin to melt.
What effect does a greenhouse have on the
temperature? Do this experiment to find out.
 |
2 thermometers
|
 |
A large clear glass or plastic
jar
|
|
On a sunny day lay the two thermometers
side by side on the same kind of surface outdoors. Leave the
thermometers for two or three minutes and then write down the
temperature shown by each of them.
|
Temperature after 2/3
minutes:
|
|
Thermometer 1
|
|
|
Thermometer 2
|
|
|
| |
|
|
Cover one of the thermometers with the
large jar. This is your greenhouse.
|
| |
|
 |
Read the temperatures shown by the two
thermometers after 30 minutes and again after one
hour.
|
Temperature after 30
minutes:
|
|
Thermometer 1
|
|
|
Thermometer 2
|
|
|
Temperature after 1
hour:
|
|
Thermometer 1
|
|
|
Thermometer 2
|
|
What difference in temperature, if any, is
there?
|
 |
Scientists call the way in which gases
high in the sky are affecting the Earth's temperature, the
'greenhouse effect'. What can we do to slow down or stop the
greenhouse effect? Write your ideas in your
workbook.
|
|
 |
 |
