Given below is a representation of a type of pollution. Study the picture (factories and vehicles emitting smoke, with a person coughing) and answer the questions: Given below is a representation of a type of pollution. Study the picture (factories and vehicles emitting smoke, with a person coughing) and answer the questions:
State one gaseous compound that leads to the depletion of the ozone layer and creates ‘Ozone holes’.
Topic: Ozone depletion
Answer
CHLOROFLUOROCARBONS (CFCs).
CFCs were used as refrigerants, in air conditioners and as aerosol propellants.
HOW THEY DESTROY OZONE: they rise to the stratosphere, where ultraviolet light breaks them down and releases CHLORINE atoms. Each chlorine atom destroys thousands of ozone molecules, which is what produced the OZONE HOLE over Antarctica.
WHY IT MATTERS: a thinner ozone layer lets more ultraviolet radiation through, causing skin cancer, cataract and damage to crops.
KEEP THE THREE PROBLEMS SEPARATE, since papers test whether you can: CFCs cause OZONE DEPLETION; carbon dioxide and methane cause GLOBAL WARMING; sulphur and nitrogen oxides cause ACID RAIN. Different gases, different consequences.
CFCs were phased out under the MONTREAL PROTOCOL of 1987, and the ozone layer is slowly recovering.