Question 31
When chlorofluorocarbons (CFCs) were invented in 1928, these gases were thought to be very useful because they are not reactive, non-toxic and non-flammable. In the 1980s, scientists began to present evidence from space of a hole in the ozone layer. The ozone layer is a thin part of the Earth’s atmosphere. It protects the Earth from harmful ultraviolet (UV) radiation from the Sun.
Scientists eventually discovered that when CFCs get to the ozone layer, the Sun’s UV radiation breaks down the bonds between carbon and chlorine in CFCs, releasing chlorine atoms. The chlorine atoms react with ozone molecules ($O_3$). This process reduces the amount of ozone in the ozone layer.
The Montreal Protocol, signed in 1987, is an international agreement made by many countries to protect the ozone layer. The Montreal Protocol aims to reduce and eventually stop the production and use of chemicals that damage the ozone layer, such as CFCs.
Look back at the question at the start of the chapter. Why does the impact of CFCs on the environment affect the whole world?
Scientists eventually discovered that when CFCs get to the ozone layer, the Sun’s UV radiation breaks down the bonds between carbon and chlorine in CFCs, releasing chlorine atoms. The chlorine atoms react with ozone molecules ($O_3$). This process reduces the amount of ozone in the ozone layer.
The Montreal Protocol, signed in 1987, is an international agreement made by many countries to protect the ozone layer. The Montreal Protocol aims to reduce and eventually stop the production and use of chemicals that damage the ozone layer, such as CFCs.
Look back at the question at the start of the chapter. Why does the impact of CFCs on the environment affect the whole world?
