CFC's are banned in the U.S. because they cause ozone to degrade. Which part of our atmosphere does this protects and why it is important?
The layer of the Earth's atmosphere that is impacted by chlorofluorocarbons or CFCs is the stratosphere.
"The stratosphere is the second major layer of Earth's atmosphere, just above the troposhphere, and below the mesophere."
CFCs were developed in the early 1930s and were used in a variety of industrial, commercial, and household applications. It was not until 1984 that the damage from CFCs was conclusively linked to ozone depletion.
Ozone in the stratosphere is important becasue it acts as a primary UV radiation shield. Without this shield more UV radiation is making its way through our atmosphere and impacting humans.
"It is suspected that a variety of biological consequences such as increases in skin cancer, cataracts, damage to plants, and reduction of plankton populations in the ocean's photic zone may result from the increased UV exposure due to ozone depletion."
CFC (chlorofluorocarbons) is a type of synthetic organic compounds containing chlorine, fluorine, and carbon. There are several types of CFC's such as trichlorofluoromethane, (CFC-11) and dichlorodifluoromethane, (CFC-12). CFC's are used as refrigerants in air conditioners and refrigerators and to make plastic foam for furniture and insulation.
CFC's harm the environment by breaking down ozone molecules in the earth's upper atmosphere. This part of the earth is also called Ozone layer because of the presence of ozone, that helps to reduce the amount of harmful ultraviolet radiations reaching the earth. When CFC's reach the upper atmosphere, they break apart and release chlorine atoms, which react chemically with the ozone and convert it to ordinary oxygen gas. To avoid the harmful impact on the environment many countries have banned the use of CFC.