What is the ozone layer and why is it important to us?
When most people hear talk of the ozone layer, it rings a distant bell as most likely you learned about in in grade school. However, for those of us who didn’t follow the path to becoming scientist or biologists, this information has been stored away in some compartment along with other data that we never actually use. Concisely speaking, the ozone layer refers to a protective layer made up of naturally occurring ozone gas that shield us from the sun’s harmful ultraviolet (UV) rays by absorbing them before they make their way to Earth. In scientific terms, ozone is a molecule found to be highly reactive and which contains three oxygen atoms. It is in a continual process of being formed and broken down in the high atmosphere right above our planet, called the stratosphere.
Unfortunately, studies now show that the ozone layer is depleting by cause of the pollution discharge involving the chemicals chlorine and bromine. What this means, is that vast amounts of ultraviolet-B rays can reach Earth, and here is wherein the danger lies for us. These rays dramatically increase the possibility of getting skin cancer and cataracts.
Animals are not spared, and in fact, there is a chain reaction from effects of extra ultraviolet-B radiation reaching Earth. The powerful and damaging radiation obstructs the reproductive cycle of phytoplankton, which are single-celled organisms found at the bottom of the food chain. There is widespread concern from biologists that the diminution in phytoplankton populations will thereby decrease the populations of other animals, and thereby increasing the number of endangered species or even the extinction.
The main villain of the ozone layer can be found in your typical household. Spray aerosols, which are commonly excessively used, contain chemicals called chlorofluorocarbons (CFCs). Research has shown that industrialized countries emitted 90 percent of CFCs presently in the atmosphere in the Northern Hemisphere. If you stop and think about it, how many times have you used a spray aerosol, or seen someone use it? Now, imagine multiplying that number by the million! The problem arises when these chemicals make their way to the upper atmosphere, where they are then exposed to ultraviolet rays, and at which point they are broken down into substances such as chlorine. At this point, the chlorine reacts with the oxygen atoms in ozone and completely disintegrate the ozone molecule. As per the U.S. Environmental Protection Agency, one atom of chlorine has the power to annihilate more than a hundred thousand ozone molecules! In other words, a chlorine atom is the Terminator for the ozone molecules.
Pollution over the decades has been especially detrimental to the ozone layer above the Antarctic. The reason for this can be explained by the region’s low temperatures which accelerate the conversion of CFCs to chlorine. During periods of extended daily sunshine, the chlorine is reacting with ultraviolet rays, and causing the destruction of the ozone at an alarming rate of up to 65 percent. Moreover, the ozone layer in other regions has deteriorated by approximately 20 percent. Fortunately, the United States and Europe banned CFCs by 1996, resulting in a decreased amount of chlorine in the atmosphere. However, according to scientists, it will take half a century for chlorine levels to reverse to their natural levels. In layman’s terms, that is in a very, very long time.
In a nutshell, the ozone layer is precious to human and animal life and should be preserved at all costs. The risks otherwise are what we are currently seeing, through the increase of ultraviolet B rays that make their way to our planet, our homes, our neighborhoods, and putting us all at a much higher risk of sun damage including skin cancer.
*Data compiled/adapted from National Geographic