Environmental Issues

The fact that the world is witnessing a continuous but steady decrease is the global ozone layer is raising many concerns for the future existence of mankind. This is first because such depletions in the ozone layer are evidently increasing the amount of ultraviolet blue (UVB) rays on earth. UVB rays have been identified to have the potential of increasing skin cancer infection on earth (Parson 46). It should be noted here that the ozone layer serves to absorb the UVB rays from the sun.

Still feared is that ozone layer depletion could lead to increased ultraviolet radiations on the earth surface thus increasing the size of the troposphere ozone, an element which poses great health risk to humanity (Brooks). This makes ozone depletion a major threat to the future existence of mankind.

This paper is written as a research on the causes of ozone depletion. The author first gives a definition of ozone layer before giving an elaborative discussion on what causes ozone layer depletion. A discussion on the effects and how such can be reduced is also given.

Definition of ozone layer and ozone depletion
Ozone layer can be defined as the layer of gas in the stratosphere which serves to protect the earth from the effects of harmful ultraviolet radiation produced by the sun (Coffey). It is worth stating here that the ozone is just a colorless gas formed when ultraviolet radiations react with oxygen in the upper atmosphere of earth. Ozone layer depletion on the other side can be simply defined ass the gradual decline in the volume of the ozone in the earths upper atmosphere (stratosphere) (Books). This gradual depletion of the zone has been approximated to be at the rate of 14 percent per decade since 1970s (Brooks).

Ozone depletion has also been defined as the seasonal decline in the ozone in the stratosphere relative to the polar region of the earths surface (Go). This is usually called ozone hole and is found to be periodic but at a higher rate than 14 percent per decade. A good example is the 70 percent reduction of ozone in the Antarctica reported in 1985 (Hardy 112). It is however worth noting here that there is still another form of ozone depletion called troposphere ozone depletion. This type is usually evident near the earth surface particularly in the Polar Regions during the spring season.

Effects of ozone layer depletion
There many effects of ozone depletion. However, the most evident one is increase in ultraviolet radiations into the earth surface (Go). This has been closely attributed to the fact that ozone layer is responsible for the absorption of harmful ultraviolet radiations from the sun. This increase in UV radiations on earth has been proved to have the potential of increasing the rates of skin cancer infections in the human community.
Ozone depletion has also been found to be the reason behind the decrease in stratospheric and troposphere temperatures (Coffey). This is closely associated with the fact that reductions in the ozone layer increase the passage of ultraviolet radiations to the earth surface. It is here to be understood that the upper troposphere and the stratosphere are usually warmed by the radiations absorbed by the ozone. This is a reason behind global warming.

Causes of ozone depletion
Although many have claimed natural causes of ozone depletion, most of the qualified causes of ozone depletion are due to mankind activities. The main cause of ozone depletion is the ever increasing number radical particles in the upper atmosphere (Brooks). Such include hydroxyl and nitric radicals. Others like chlorine and bromine have also a crucial function in causing ozone depletion. It is evidently clear from scientific research finding that the ozone layer is a colorless gas resulting from the reaction of ultraviolet radiations and oxygen in the stratosphere (Hardy 117). Still clear is the fact that radical particles have a high affinity for oxygen. This means that the presence of such radical particles will reduces chances of forming ozone thus leading to its reduction.

It is however to be noted that 80 percent of ozone depletion is caused by the presence of chlorofluorocarbons and hydroflourocarbons in the upper atmosphere (Brooks). Scientific finding evidently show that this compound is quite stable in the lower atmosphere. It is nevertheless clear that the compound breaks down in the stratosphere releasing atomic chlorine due to the influence of ultraviolet radiation. The atomic chlorine, while in the stratosphere is found to live in a cycle of make-break molecules. It first reacts with a molecule of the ozone gas forming a molecule of oxygen and chlorine monoxide (Parson 54). The chlorine monoxide further reacts with another ozone molecule forming chlorine atom and oxygen. This means that the chlorine atom can now repeat the reaction process again. This is what makes chlorofluorocarbons a major cause of ozone layer depletion as the reaction process continues infinitely.

Halons are also another major cause of ozone layer (Coffey). Though scientific thought to be safe and inert, such chemical components are quite detrimental once they degrade in the stratosphere. The most common threat to the ozone layer is the bromine atom (Hardy 119). Once in the upper atmosphere, halogen degrades due to influence of the high energy ultraviolet radiations presence. This leads to the production of bromine which reacts with the ozone gas molecules the same way as chlorine atom. It is to be noted here that scientist have evidently claimed that halons last over 100 years (Go). This means that once in the stratosphere their reaction with the ozone layer will last those many years. It is there clear that chlorofluorocarbons and halons are the biggest threat to ozone depletion (Parson 61). This is further complicated by the fact that such components are still being produced and used across the globe.

Other man made causes of ozone depletion include chemical components like methyl bromide and methyl chloroform (Go). It is worthy noting here that such chemical are widely used in the community for making pesticides and as industrial solvents respectively. This means that they are crucial factor in the ozone depletion problem. Still clear is the fact that once in the upper atmosphere, methyl bromide break to produce bromine while the methyl chloroform degrades to form atomic chlorine (Coffey). Just to be made clear here, it ha been evidently established through research that bromine atoms are much more reactive and thus more destructive to the ozone than chlorine atoms.

It has also been established that ozone hole as found in the Antarctica can be caused by the reactions between the polar stratospheric clouds (Parson 63). This is because such reactions are the reason behind the low stratosphere temperature. It is to be noted here that lowering of stratospheric temperature is due to reductions in the ozone layer thus increasing the amount of ultraviolet radiations reaching the earth surface. It is based on this reasoning that reactions between polar stratospheric clouds lead to ozone depletion.

Conclusion
In conclusion, it is evidently clear from the research findings tat the major cause of ozone depletion is mankind. This is because he is the major producer of halons and chlorofluorocarbons which are the leading causes of ozone layer depletion. It should be in the interest of saving the future of humanity that the right measures and devoted cooperation should be adopted to eliminate andor reduces the production of such components in the society.