Data
Analysis and Interpretation
1. It took 25 yrs for CCl3F to enter the stratosphere (1930 to 1955).
2. The ozone layer above Canada began to decline in 1975.
3. Once the production of CCl3F was drastically reduced, it took 20 years for the CCl3F levels to decrease in the stratosphere.
Conclude and Communicate
4. CFCs (Chlorofluorocarbons) are inorganic man-made chemicals that have been in production for more than 50 years in Canada. They were thought to be sensational substances due to their stability, nonflammable characteristic, low in toxicity, and inexpensive. However, research on CFCs showed that they have long life spans allowing them to resist being washed away in rain. Through the aid of wind, CFCs rise up into the stratosphere and into the ozone layer where they decompose into chlorine and bromine, from the ultraviolet radiation. These two chemicals are responsible for damaging the ozone layer. Some atmospheric chlorine are caused by natural occurrences such as large fires and volcanic eruptions, yet most chlorine in the ozone layer is due to CFCs from man-made products such as refrigerators, aerosols, solvents and other household items. Studies show that for every one chlorine atom that is released into the ozone layer, 100000 ozone molecules are destroyed. According to the statistics recorded in 1979, the ozone layer has decreased every single decade nearly 4% to 6% in mid-latitudes and 10% to 12% in higher southern latitudes. This constant decrease has left the ozone layer permanently damaged. Even though production of CFCs has drastically decreased over the past couple of years, the ozone layer is unable replace itself.
Research on how Earth is affected by the depletion in the ozone layer
5. CFCs are so stable that the only way to break them is by exposure to strong UV radiation. When this occurs, the CFC molecule releases chlorine that can destroy 100000 ozone molecules. Because of this