June 29, 2009
Causes of Ozone Depletion
What are the most well-known causes of ozone depletion? You've probably heard about the ozone layer at some point in time. No doubt you've heard that some environmental problems change or reduce the ozone layer and others cause the world to heat up. But what is the ozone layer?
Here are some answers about this mysterious layer of gas that surrounds the planet, the ways it protects us, and why it is disappearing.
The Ozone Layer - a Primer
Ozone, a gas comprised of three oxygen atoms bonded together as O3, surrounds the planet's atmosphere. Its unique properties allow it to absorb UV-B rays from the sun, rays that can be detrimental to all life on earth. UV-B causes skin cancer and is normally associated with sunburns and overexposure to the sun's rays. Regular sunburns however are merely caused by overexposure to UV light, but UV-B light passes through the skin and directly affects the DNA, which is what causes the cancerous growths seen in melanoma as well as some non-cancerous growths.Ozone absorbs most of the bad energy that comes down from the sun, but it's also hazardous to breathe, which is why we need it to stay so high up in the atmosphere.
About the causes of ozone depletion...
We could identify many causes of ozone depletion, but the main cause is simple: mankind. Man produces chemicals of all sorts that nature never devised. Chlorofluorocarbons (CFCs) have been used as propellants in aerosol cans, foaming agents, and as a coolant. When ozone is in the presence of chlorofluorocarbons, it breaks down. Because of the way ozone is formed, the CFC acts as a catalyst to make it easier to break it down that make it, resulting in ozone layer depletion. Other offending chemicals include methyl bromide (a pesticide), methyl chloroform (an industrial solvent), and carbon tetrachloride, which is used to make chlorofluorocarbons. These chemicals are all recognized ozone depleters, and they don't break down easily, if at all, so they stick around for quite some time in the atmosphere, compounding the damage they do.The consequences of depleted ozone are serious, and include a laundry list of illnesses and plagues. Skin cancer, animal and crop mutations, lowered crop yields, and even a reduction in the amount of plankton in the ocean. While the amount of plankton may not seem as serious as skin cancer, it is the bottom of the marine food chain, and affects almost every form of marine life, causing effects that eventually reach man in his food supply. A hole in the ozone layer above the Antarctic pole worries scientists as solar energy left unchecked pours into the lower atmosphere.
You may be asking yourself what we can do to control the causes of ozone depletion, and that, too, is a relatively simple answer. We can control the sources of ozone-depleting chemicals and work to reduce their production and use. The more complicated part of that strategy is implementing it in a world where airplanes fly high enough in the atmosphere that their emissions disrupt the ozone layer and spray cans still need propellant. Non-CFC propellant is available, but in some cases it is not as effective or more it costs too much, which makes it unattractive for industrial use, where overhead and production expenses are trimmed at every opportunity.