(a) ways in which human activities affect the composition of the atmosphere ;
(i) Emission of carbon dioxide, e.g burning fossil fuel such as coal, petrol gas
(ii) Deforestation
(iii) Use of chemical, biological and nuclear warfare
(iv) Release of toxic waste
(v) Bush burning
(vi) Pollutants emitted from industrial activities
(vii) Pollutants emitted from mining and construction works
(b) physical changes that are likely to be associated with the increasing reduction of the ozone layer in the upper atmosphere
(i) As the ozone layer increases the amount of ultra-violet rays increases in the atmosphere
(ii) The increase in ultra-violet rays increases the amount of solar radiation at the earth's surface
(iii) Excessive ultra-violet rays leads to increase in skin cancer in man
(iv) Increased temperature leads to melting of polar ice and this leads to rise in sea levels.
(v) Possible increase in precipitation
(vi) Death of chlorophyll in plants leads to inability of plants to manufacture food.