Ozone Report: The Knowledge of Cfcs

CFC’s, also known as chlorofluorocarbons, are a group of compounds that contain atoms of carbon, chlorine, fluorine, and occasionally hydrogen. Prior to the creation of CFC’s, refrigeration systems, as well as air conditioning systems, relied heavily on other compounds that were easily flammable and toxic which rendered them a danger to the public. The compounds that were used during this time included chemicals such as ammonia, chloromethane, propane, sulfur dioxides, and many others; all of which could cause serious injury and harm. Then, in 1928, an American man named Thomas Midgley, with the help of his team completed the creation of CFC’s to be used in place of the harmful chemicals in refrigeration and air conditioning systems. The advantage of the CFC’s in contrary to the chemicals previously used is that they were non-flammable and non-toxic to humans. As the knowledge of CFC’s being a safe replacement for other chemicals became more and more widespread, CFC’s began to get mass produced worldwide and were applied in many other systems such as foam-blowing, aerosols, and cosmetics. By the 1970’s, CFC’s were being used in production worldwide with an estimate of nearly one million tons being produced per year. Due to the extensive capacity at which CFC’s were being produced and used, they were being emitted into our atmosphere in large quantities which affected the condition of the ozone layer.

The ozone layer is a layer surrounding Earth high in the atmosphere. It is located specifically in the stratosphere and troposphere and is found an estimated 10 to 30 kilometers above the earth’ surface. The ozone layer is essential to life on earth as it protects all living beings from the suns’ harmful ultraviolet rays. The ozone layer filters and absorbs much of the radiation which shields the earth’s surface from high UV exposure. This is crucial because studies have proven that plants, animals, and human beings are subjected to harmful effects when exposed to large amounts of radiation. The ozone layer contains substantial amounts of ozone which is a special type of oxygen; it is three oxygen atoms bonded together (O3). Ozone is a rare chemical found in our atmosphere but plays a very important role which makes the disruptions of the ozone layer by CFC’s all the more concerning. When CFC’s are at sea level, they are very stable compounds and do not react highly. But, when they begin to drift upward and are in the atmosphere, the ultraviolet radiation emitted from the sun breaks up the compound and splits off a chlorine atom. Once this occurs, the highly unstable chlorine atom that contains an unpaired electron will be loose in the atmosphere. The single chlorine atom will then split the ozone molecules to try and combine with a single oxygen molecule to create a stable compound; chlorine monoxide. A single chlorine atom can react with and destroy up to 100,000 ozone molecules before finally bonding with one which is why small amounts of CFC’s can have such a large impact on the ozone layer. Furthermore, once a chlorine molecule has stabilized itself with an oxygen molecule, the UV rays will simply break it up again creating an almost infinite cycle. Even since the use of CFC’s have been stopped internationally, CFC’s in the past have already broken down the ozone layer, making it thinner and weaker all over the world. But, it has had an especially big impact on the Arctic and Antarctic regions since the lower temperatures there cause the chlorine atom to be broken off faster form the CFC than in warmer climates. The use of CFC’s in the past, have made the ozone weaker in general and less effective at filtering out and absorbing damaging UV rays.

During the 1970’s there were concerns raised by scientists Paul Crutzen, Mario Molina, and Sherwood Rowland in regard to the effects of CFC’s on the ozone layer. And by 1978, the thinning of the ozone was a large topic of conversation in the public. They were concerned about large emissions of CFC’s over the years possibly causing a catastrophe to occur in the ozone layer. Despite the concerns, during this time there was nothing that was identified in the ozone layer that suggested that something was wrong and the layer appeared normal. A scientist with the British Antarctic Survey began to monitor the ozone layer and soon discovered that since the 1970’s, the ozone values had been going down in several regions around the world. By 1981, scientists could tell that there was something flawed with the ozone layer, but couldn’t pinpoint the exact problem. Then, one day in 1984, scientist discovered a large hole in the ozone layer above Antarctica that had seemed to appear out of nowhere in their data. Of the two research teams stationed in the region, scientists with the British Antarctic Survey were the first to discover the perplexing hole and shared it with the public. Despite this, many still didn’t know what to think of the hole; they thought that it could have been a malfunction or error in the systems. Then, in late 1984, scientists at NASA and all over the world had collected more data in regard to the hole in the ozone and how it was caused. Therefore, the hole in the ozone layer was confirmed as real.

As stated before, the ozone layer plays a huge role in life on earth. The reduced ozone layer, especially in the Antarctic region, where the ozone hole lies, has allowed more UVB radiation to enter through the earth’s atmosphere. This has caused multiple environmental and health issues. In regard to health issues, increased exposure to UV rays has been scientifically proven to cause various health conditions in humans such as increased risks of skin cancer, damage to the eyes, and impairment of the immune system. As a comparison, prior to the 1980’s, sunscreen was not heavily worn by the public since the ozone layer was strong and filtered out most of the harmful UV rays. But currently, if we go outside without sunscreen on, it is very likely that we will end up with a sunburn since the UV index is much higher due to the depletion of the ozone. Furthermore, the increase of UV rays, have affected the growth of plants and phytoplankton and since they are the producers in almost every food chain, it greatly affects a large number of ecosystems. Once scientists had discovered the effects of CFC’s on the ozone layer, they all quickly came to an agreement that it must be stopped. Therefore, in 1987, an international agreement was signed, called the Montreal Protocol, which started the phasing out of all chemicals that damaged the ozone layer, including CFC’s. This protocol has helped control the damage done to the ozone layer and continues to protect the layer while it recovers to this day. Scientific studies and monitoring of the ozone layer confirms that it is recovering and estimates that it should be back to its original state by the 2040’s.

In 1974, a controversial hypothesis was made about CFC’s by scientists Drs. F. Sherwood Rowland and Mario Molina. They believed that CFC’s where able to rise into the stratosphere where they would break up, release a chlorine atom, and damage the ozone molecules. However, when they first introduced this idea, most people didn’t believe them since there was not much evidence and the condition of the ozone layer seemed fine. Then in 1985, the shocking discovery of a hole in the ozone layer was published. Scientists were perplexed by this occurrence and began to do more research as to how the hole formed. Through their research, scientists were able to discover that in the years where the amount CFC’s in the stratosphere were increasing, the ozone levels were decreasing. So, with the new discovery and increased evidence, the correlation was made between CFC’s and the destruction of the ozone molecule, identifying CFC’s as the main source of ozone depletion.

With the use of CFC’s now reduced, new chemicals had to be used in place of CFC’s to run the various jobs that they covered. One of the main chemical used currently in place of CFC’s is a compound called HFC’s or hydrofluorocarbons. HFC’s are very similar to CFC’s except for the fact that they don’t contain chlorine, therefore, they will not deplete the ozone layer when emitted into the atmosphere. HFC’s have been used as coolants and propellants in systems such as air conditioners, refrigerators, aerosols, and many others. Despite the lack of harm that it does to the ozone layer, HFC’s are very strong greenhouse gases which pose a different kind of threat in the form of pollution and climate change. Because HFC’s don’t deplete the ozone layer, they are often marketed as environmentally friendly. But, on the contrary, HFC’s are a potent greenhouse gas, more powerful than carbon dioxide, which has a long atmospheric life of 14 years up to 260 years. Furthermore, HFC’s are estimated to be responsible for 8.6% of all global greenhouse gas emissions over the next 20 years. Therefore, even though we have invented a solution for ozone depletion by CFC’s, we have yet to think up a solution with no disadvantages to the environment.

With the constant and delicate monitoring of the ozone by scientists all over the world, we are able to identify the state of our ozone today; 30 years from when the Montreal Protocol was signed. CFC’s are capable of staying hidden in the atmosphere for 40 to 150 years, which why we are still feeling the impacts of previous mass CFC use. While, the ozone hole in the Antarctic is the area where the ozone layer is the most depleted, the ozone is generally thinner and weaker as a whole due to the emission of CFC’s. Studies conducted by scientists show that the hole in the ozone layer was at its largest in 2015, but has begun to repair itself in the years following. Although the state of our ozone layer today is not perfect, it has begun to recuperate with the help of the Montreal Protocol and is estimated to return to the state it was in during 1980 by the year 2040.